Seller disclosure: XES Netting manufactures bale net wrap. We do not sell mowers, tedders, rakes, weather services, or forage testing, and we earn nothing from any brand, app, or lab named below. The research figures cited here come from published university forage work; the field judgment comes from producers on public forums, quoted verbatim with source links.
Short answer: Cut when the crop is at or past prime and the forecast gives you a genuine drying window; wait when the crop is still gaining quality and the pattern is unsettled. The number that matters is not the percentage chance of rain — it is how much, for how long, and what the weather does afterward. Rain on a freshly cut, still-respiring crop above 50% moisture costs far less than the same rain on hay that is nearly dry. Documented dry-matter losses from a soaking on partly cured hay run from 6% to 34%. If the pattern never opens, wrapping the crop as baleage at 45–55% moisture is a legitimate third option, not an admission of defeat.
Nearly everything written about rain and hay is written after the rain. Our own guide to what to do with rained-on hay is a salvage manual: you have a soaked windrow, now what do you test, what do you disclose, what will it feed. That guide starts at the moment the decision has already gone wrong.
This one starts earlier, at the gate, with the crop still standing and a forecast on the phone. Do you drop it today or leave it up? That is a different question with a different answer, and it is the question producers actually argue about. Below: what the crop loses by waiting, what rain actually costs when it lands, why timing beats total inches, how experienced producers read a forecast, the market penalty nobody puts in a spreadsheet, and the wrap-it-instead option.
What you are actually trading
The cut-or-wait call is a trade between two losses that move in opposite directions.
Waiting costs quality on a schedule. Standing forage keeps maturing. Fiber climbs, digestibility falls, and the leaf-to-stem ratio moves the wrong way. That loss is slow, predictable, and certain.
Cutting costs quality by lottery. If the window holds you bank a premium crop. If it fails you take a hit that ranges from trivial to catastrophic depending on how far along the hay was when the rain arrived.
The critical insight, and the one that reframes the whole decision, is that the waiting penalty shrinks as the crop gets more mature. Once a stand is already past prime, another three days of standing costs comparatively little — you have already taken most of the quality hit. A producer posting as rjmoses laid this out precisely:
"Both alfalfa and grass have already gone past prime, so waiting a while longer won't be costing me much more in terms of quality. So I'm trading off food value quality for storage quality by waiting longer."
— rjmoses, HayTalk thread 19714
That is the whole calculus in two sentences. Early in the season, with a crop still short of bloom, waiting is expensive and a marginal window may be worth taking. Late, with a crop already headed out, waiting is cheap and there is little reason to gamble.
There is a limit, though, and it runs the other way. Leave a mature crop standing long enough and weather damages it where it stands:
"When the stuff gets mature enough the rain will ruin it while it is standing"
— endrow, HayTalk thread 19714
Lodged, weathered, bleached standing forage is not preserved forage. "Wait for a perfect window" stops being a strategy somewhere around the point the crop starts falling over.
What rain costs: the measured losses
The reason this decision feels unresolvable is that the penalty is genuinely variable. It is not one number. Published forage research puts real bounds on it, and the spread is the point.
The mechanism first: a cut plant keeps respiring — burning its own sugars — until it dries below roughly 50% moisture. Respiration essentially stops there. Rewetting partly cured hay restarts it, and that restarted respiration, plus leaching of soluble nutrients and extra mechanical handling, is where the loss comes from.
Measured dry-matter losses reported in university trials summarized by Hay & Forage Grower:
| Rain event | Reported dry-matter loss |
|---|---|
| 1 inch, after one day of wilting (Wisconsin) | 22% |
| Heavy event on partly cured hay (Michigan) | up to 34% |
| ~¾ inch spread over 1–7 hours (Michigan) | 6%–12%, worst with longer duration |
Quality moves too, and not always the direction people expect. In Wisconsin work, a 1.1-inch event raised NDF by about 4 to 5 percentage points; a 1.9-inch event spread across eight days raised it 12 to 13 points. Crude protein percentage can actually rise after moderate rain — not because protein was added, but because soluble carbohydrates leached out and protein became a larger share of what remained. A hay test showing decent CP on rained-on hay is not evidence the rain was harmless.
Two conclusions worth carrying to the field gate:
- Duration hurts more than volume. The same three-quarters of an inch cost twice as much dry matter when it fell over seven hours instead of one. A short hard shower that runs off is not the same event as an all-day drizzle.
- A single moderate rain is survivable. Losing 6–12% of the dry matter and a few points of NDF is a bad day, not a lost crop. Repeated wetting across many days is what produces the ruinous numbers.
Why when the rain lands beats how much falls
This is the single most useful thing to understand, and it is why blanket rules like "never cut with rain in the forecast" are wrong.
Rain on a freshly cut crop still above 50% moisture does relatively little harm. The plant is still respiring anyway, the tissue is still intact, the soluble nutrients are still inside cells that have not been ruptured by drying and handling. Water largely runs off a fresh, heavy swath.
Rain on nearly dry hay is the expensive event. Cell walls are brittle, leaves shatter, and the crop soaks up water like a sponge, restarting respiration in material that has already spent days losing sugars.
The practical consequence is counterintuitive: if rain is certain in roughly 24 hours, cutting immediately may beat waiting. You get a day of drying, take the rain on a wet crop that tolerates it best, and resume with the remaining moisture to remove. Waiting instead means cutting into the recovery period and starting from scratch on wet ground.
Producers arrive at this by experience. One who cuts with a disc mower and owns a tedder puts hard conditions on it:
"I cut just before rain or during rain a lot but only when the forecast is strong for good weather the next day for several days. I cut with a discbine which can cut anything regardless of how wet. Immediate tedding following the rain before the sun cooks it is essential for eliminating mold and mildew at the bottom of the hay especially as the heat increases to mid 80s or above."
— Hayman1, HayTalk thread 22931
Note the conditions attached: a disc mower rather than a sickle-bar haybine, a tedder on hand, and a genuinely strong multi-day forecast afterward. Strip those away and the same move is reckless. In the same thread another producer, without that kit, is told plainly not to try it.
And the honest counterargument, from someone who has been burned by trusting the recovery:
"I just try to avoid it if possible. The way the weather changes anymore if you cut in the rain it may not end for days regardless of what the forecast says.. I also don't cut right before a rain anymore for the same reason."
— mlappin, HayTalk thread 22931
Both are right. The cut-before-rain play depends entirely on the after forecast being reliable, and that is exactly the part of a forecast that degrades fastest beyond about 48 hours.
For how to compress the drying side of this equation once the crop is down, see how to make dry hay faster and wide swath vs narrow windrow. Note one direct interaction with this decision: a wide swath dries fastest, but a narrow windrow sheds water better. When you cut expecting to take a shower, narrowing up is a defensible trade.
Reading a forecast like a hay producer
A percentage chance of rain is the least useful number on the screen, and experienced producers treat it as such.
First, the percentage is not stable across seasons or patterns:
"Depends. Some years, a 50% chance of rain means it probably won't rain; some years, like this year, a 20% chance means it probably will rain."
— rjmoses, HayTalk thread 19714
A career aviator who hays makes the same point about convective weather, where the percentage is most misleading:
"I've encountered some of my worst weather conditions when the forecasters predicted a 20% chance of thunderstorms."
— jturbo10, HayTalk thread 19714
A scattered-storm forecast means low odds at any one point and near-certainty somewhere in the county. That is a different risk profile from a frontal system at the same stated percentage, and the number alone does not distinguish them.
What producers actually weigh instead:
"The chance of rain is important but perhaps even more so is the forcasted amount, duration and weather after the event. A quarter inch in one day with sun and low humidity the next isn't bad and I don't worry too much about it but but a two or three day event, even if not real heavy, and then hot and humid after is really bad."
— covenanthay, HayTalk thread 19714
That matches the research exactly: duration and post-event drying conditions drive the loss, not the headline probability. A working checklist, in priority order:
- Forecast amount — a quarter inch and an inch are different events entirely.
- Duration — the same total over seven hours costs roughly double what it costs over one.
- The weather after — sun and low humidity behind the system can rescue the crop; hot and humid behind it invites mold.
- Ground moisture going in — saturated ground adds drying days before you cut a blade.
- Season and sun angle — later in the year means lower temperatures, weaker sun, and an extra drying day in the plan.
- Only then, the percentage.
Two habits worth stealing. Cross-check multiple sources rather than trusting one app, and watch the radar trend rather than the icon. As one producer put it:
"I don't like to cut with 30 percent or higher chance of rain but I watch the radar also."
— kyfred, HayTalk thread 19714
A common personal threshold lands around 30%, with the caveat that it is a regional and seasonal setting, not a law:
"Generally, I won't cut if The Weather Channel calls for a 30% chance or higher. I usually disregard 10% and 20% chances. However, if I were in a wetter climate, I might take more chances."
— terraceridge, HayTalk thread 19714
That last clause matters. In a genuinely wet climate, holding out for sub-20% windows means never cutting at all. The threshold has to be calibrated to how many clean windows your region actually delivers.
The market penalty nobody models
Agronomic loss is only half the cost. If you sell hay, the rained-on label carries a market penalty that is often steeper than the measured feed-value loss — and it is remarkably consistent across regions.
"I have always found that it is easier to sell hay that is ripe than hay that carries the stigma of "rained on". The question of whether it was rained on is usually the first or second question the customer asks....here."
— Vol, HayTalk thread 19714
This changes the math in a way a forage test does not capture. A buyer purchasing horse hay is not running a TDN calculation; they are asking a yes-or-no question and pricing on the answer. Mature, stemmy, never-rained hay frequently outsells higher-testing hay that took a shower.
So the trade is not purely quality-versus-quality. For a hay seller, it is measured feed value versus marketability, and marketability is unusually binary. If your crop is destined for your own cows, weight the research numbers. If it is destined for a customer who will ask that question, weight the stigma.
For what to disclose when the answer is yes, our rained-on hay guide covers seller disclosure in detail.
The third option: wrap it instead of drying it
The cut-or-wait framing has a hidden assumption — that the crop has to become dry hay. Drop that assumption and a pattern that never opens becomes workable.
Baleage needs a fraction of the field time. Instead of three to five days of drying for alfalfa, you wilt to roughly 45–55% moisture — frequently achievable in a single day — bale, and wrap. A crop that cannot possibly reach 15% before the next system can often reach 50% between showers.
Producers reach for this exactly when the forecast closes:
"My long range forecast looks like rain all month on accu weather. So I'm dropping as much as a I can tonight but I'm planning on wrapping it all for now."
— Dill, HayTalk thread 19714
Being straight about the tradeoffs, since we sell wrap and have every incentive to oversell this:
- It costs more per ton. Film, wrapping labor, and heavier bales to move. Our dry hay vs baleage comparison runs the numbers.
- The market is thinner. Wrapped bales are heavy, awkward to haul, and must be fed within days of opening. Horse buyers largely will not touch it. In a year when everyone wraps, local baleage can be genuinely hard to move.
- It is unforgiving of sloppiness. Wrong moisture, delayed wrapping, or too few film layers produces spoiled feed rather than merely mediocre feed. See wrapping wet hay and the first-time baleage guide.
- It is not a rescue for already-soaked hay. Wrapping a crop that has been rained on repeatedly ferments contamination along with the forage.
Used deliberately — as the plan when the pattern is closed, not as a panic move — it converts an unwinnable week into stored feed.
The decision table
| Situation | Call |
|---|---|
| Crop past prime, 3+ clear days, low humidity | Cut now. Waiting costs quality and buys nothing. |
| Crop short of prime, unsettled pattern, no clean window | Wait. The crop is still gaining and the gamble is poor. |
| Light rain in ~24 h, then a strong multi-day window | Cut if you run a disc mower and own a tedder. Take the rain wet. |
| Multi-day event, hot and humid behind it | Wait regardless of maturity. This is the ruinous case. |
| Pattern closed for weeks, crop deteriorating standing | Cut and wrap at 45–55% moisture. |
| Selling to horse buyers who ask the question | Weight toward waiting. The stigma outruns the test. |
| Ground saturated from recent rain | Wait for the ground. Add drying days to any plan. |
| Sickle-bar haybine, no tedder, marginal window | Wait. You lack the equipment to recover. |
One habit that outperforms any table: keep notes. Record what you cut, what the forecast said, what actually happened, and what the hay ended up worth. After a few seasons your own records beat any general rule, because they are calibrated to your ground, your equipment, and your local forecast bias.
Where net wrap fits
We manufacture net wrap, so here is the honest scope of what it does and does not do in this decision.
It does not prevent rain damage in the field. Nothing on a baler helps a crop lying in a windrow. The cut-or-wait call is made and lost long before the baler runs.
Where it genuinely matters is the speed and the shed afterward:
- Baling speed inside a short window. Net wrap takes two to three revolutions to close a bale where twine takes twenty or more. When the difference between finishing a field and getting caught is thirty minutes, that is the margin. See net wrap vs twine.
- Shedding water on stored bales. A firm net-wrapped bale sheds rain far better than a twine-tied bale, whose surface channels water inward. Details in does net wrap breathe and shed water.
- Holding shape under film. If you take the baleage route, net wrap under stretch film keeps the bale dense and round so the film seals — covered in net wrap under plastic film.
And one caution that belongs in a rain article: if you bale tough to beat weather, monitor the stack. Bales made above safe moisture heat, and heating is a fire risk — see hay bale heating and fire prevention and baling moisture for net-wrapped bales. A moisture tester is the cheapest insurance in the whole operation.
The bottom line
Stop treating the percentage chance of rain as the decision variable. Ask instead: how mature is the crop, how much rain, over how long, and what happens behind it.
If the crop is past prime and the window is real, cut. If the crop is still gaining and the pattern is junk, wait — a mature crop loses little by standing a few more days, and never-rained hay sells on reputation alone. If rain is certain but brief and the recovery looks strong, cutting into it can be the right aggressive play, provided you own the equipment to recover. And if the pattern simply will not open, wrap it and stop fighting.
A grower in the mountains summed up the whole business better than any decision table:
"Dry weather will scare you to death, wet weather will starve you to death."
— blueridgehay, HayTalk thread 19714
Frequently asked questions
Should you cut hay if rain is in the forecast?
It depends on crop maturity and the shape of the event. If the crop is past prime and rain is brief with strong drying behind it, cutting is often correct because waiting costs quality anyway. If the crop is still gaining quality, or the event runs multiple days with hot humid weather behind it, wait.
How much rain ruins cut hay?
There is no single threshold. University trials report dry-matter losses from 6% to 12% for about three-quarters of an inch, roughly 22% for a one-inch event after a day of wilting, and up to 34% in the worst measured cases. Duration matters more than total amount, and repeated wetting causes the severe losses.
Is it better to cut hay before rain or after?
Cutting before is often better if the rain is brief and good drying follows. Rain on a freshly cut crop above 50% moisture causes far less damage than rain on nearly dry hay, because respiration has not stopped and cells have not become brittle. Cutting after means waiting for saturated ground to dry first.
What percent chance of rain is too high to cut hay?
Many producers use roughly 30% as a personal cutoff and disregard 10% to 20% chances, but the percentage is the weakest input. Forecast amount, duration, and the weather following the event predict losses far better. In wet climates a stricter threshold means never cutting at all.
Can you bale hay as baleage instead of waiting for dry weather?
Yes. Baleage is wilted to about 45% to 55% moisture rather than 15%, often achievable in a single day, then baled and wrapped in stretch film. It costs more per ton, sells into a thinner market, and demands correct moisture and prompt wrapping, but it converts a closed weather pattern into stored feed.
Written by the XES Netting team. We manufacture bale net wrap and read the farmer forums so the people doing the work can find clear, source-cited answers faster. Every quote in this post is verbatim with a source link — go read the originals.
Hero image: Haymaking — tractor and mower cutting grass, by David Joyce on Wikimedia Commons, used under CC BY-SA 2.0.
