Somerset Weather · Hyper-local Forecast

On the farm fall

For grain farms around the Somerset station: the station, its ground sensor beside the field, and our hyper-local forecast, turned into the day's field decisions. Updated every hour.

Harvest hours, next 48 hours Experimental

Tomorrow: dew off about 9 AM, damp again about 3 AM. Right now the grass probe reads 47.2° against a dew point of 35.2°: no dew. Soybean pods take up moisture from humid air and shatter when too dry; most harvest happens in the good and fair hours. Dew comes on when the grass cools to the dew point (from the ground probe and the physics model) or the humidity passes 90%, and burns off in daylight once the humidity falls to 75%. These timings are new: we're checking them against the probe this fall.

Drying in the field Experimental

"Heading toward" is the moisture corn left standing would settle at if the day's average temperature and humidity held (the equilibrium moisture of shelled corn, the engineering standard's equation). Grain wetter than that dries; drier grain takes moisture back. Good: heading to 14% or below with at least four dry hours and no rain. Poor: above 17%, or a tenth of an inch of rain. Ears in the husk dry slower than this; it is the direction and the pull, not a promise.

Your corn Experimental

Enter a moisture test from your field (remembered in this browser). The estimate starts from typical field drydown for the date (Purdue Extension: about 0.9 points a day in early September, 0.65 late September, 0.5 early October, 0.4 late October, 0.1 in November), faster on days warmer than normal and slower on cooler ones (by the day's growing degree days against normal), slowing as the grain nears the air's equilibrium moisture, and none on days with a tenth of an inch of rain or more. The days since your test use the station's measurements, then our 7-day forecast, then normals. Equilibrium moisture comes from our hourly forecast for the next two days, typical values after that (13.5% in October, 16% in November, 18% in December). Hybrids, husk cover and ear angle all change real drydown: a fresh test re-anchors it.

Frost and freeze at crop height

On clear, calm nights the air at crop height runs several degrees colder than the 5-foot reading the forecasts give: the station's grass probe has measured as much as 12° colder at dusk. Tonight's crop-height low is from our physics model of the night; tomorrow night's from the detailed run's grass estimate. Frost at 32° damages leaves; a killing freeze (about 28° in the air for a few hours) ends the season for corn and soybeans that are not yet mature, and in the spring injures wheat once it is jointing (about 24°) or heading (about 30°).

Spray windows, next 48 hours Experimental

Measured now at the mast: wind 0.2 mph at 12 ft (about 0.2 mph at boom height); grass 47.2° against the air 62.6°: a surface inversion is measured right now (the grass well below the air): drift-prone sprays stay put.

Hover or tap an hour for its reasons. Wind is at boom height: the forecast 33 ft wind scaled by how much lighter this station's own 12 ft wind runs at that hour (about three quarters at midday, under half on summer nights), then down to about 20 inches above the canopy. Checks: wind 3 to 10 mph (2 to 10 for fungicide and insecticide), gusts under 15, rain-free for the hours you choose, delta T (the air minus the wet-bulb: how fast droplets evaporate) between 3.6° and 14.4° ideal and no spraying above 18°, temperature (efficacy falls below about 45°; drift-prone herbicides turn volatile in heat), and temperature inversions: calm, clear evenings and nights trap a fine spray near the ground, and the station's grass probe shows one directly when the grass runs well below the air. Dicamba labels also rule out the hour before sunset through two hours after sunrise. The product label always governs.

Soil temperature, measured in the field

Fall nitrogen: the usual guide is to hold fall anhydrous ammonia until the 4-inch soil is below 50° and falling, so less of it turns to nitrate and leaches before spring. The 4-inch probe reads 52.9°: not there yet. The probes sit at the base of the station mast, beside the field. The ground sensor went in on October 17, 2026, so the 7-day means are still filling in.

Rain

Measured by the station's gauge (September 20 to 25, 2026 from the ERA5 reanalysis: the gauge logged a glitch). Normals: 1991-2020 at this spot from the ERA5 reanalysis. The gauge is unheated: snow counts when it melts.

Growing degree days

Corn growing degree days (86/50 method) from the station's daily high and low, summed from the planting date you enter (remembered in this browser). Stages are typical for mid-season hybrids; each hybrid's own rating (its GDD to black layer) is the better guide. Soybeans follow day length more than heat, so their stages aren't shown.