If you’ve ever stood in the middle of a field during the Deerfield Fair in late September, you know that the weather in Deerfield NH is less of a predictable pattern and more of a mood. One minute you’re peeling off a flannel shirt because the afternoon sun decided to hit 75°F, and by the time you reach the Ferris wheel, you’re shivering in the shadows.
It’s New England. We’re used to it. But Deerfield has its own specific quirks.
Most people look at the general New Hampshire averages and think they’ve got it figured out. They don't. While the state's data gives you the broad strokes, Deerfield sits in a pocket of Rockingham County where the hills and forests create micro-climates that can make your backyard feel five degrees colder than the official reading at the Manchester-Boston Regional Airport.
The Winter Reality: It’s Not Just the Snow
January is, honestly, brutal. The average high struggles to reach 32°F, and the lows frequently dip into the single digits. But here's what the charts don't tell you: the wind. Because Deerfield has so much open farmland, the wind chill—what meteorologists like to call "perceived temperature"—is the real enemy.
Snowfall is a major player here. On average, the town sees about 17 inches of snow in both January and February. If you’re living on a dirt road like Reservation Road or near Pawtuckaway State Park, that's not just a statistic—that’s a morning spent with a shovel before your first cup of coffee.
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- January Cold: Average lows around 6°F, but 2026 has already seen some weird swings.
- The "Ice" Factor: We get a lot of mixed precipitation. It’s that nasty slush that freezes overnight into a sheet of glass.
- Cloud Cover: January is the gloomiest month, with about 67% cloud cover. Basically, don't expect to see the sun for a week at a time.
Mud Season: The Fifth Season Nobody Wants
Around late March, the weather in Deerfield NH enters its most chaotic phase. The snow melts, but the ground is still frozen underneath. Result? Mud. Deep, tire-swallowing mud.
Temperatures start to climb into the 40s, which feels like a heatwave after February. You’ll see locals wearing shorts when it hits 50°F in April. It’s a rite of passage. April brings about 3.4 inches of rain, and while the "April showers" cliché exists for a reason, in Deerfield, those showers often turn into late-season heavy wet snow that snaps branches because the trees are starting to bud.
Summer is Short but Sweet
By the time June 18th rolls around, the clouds finally start to thin out. This is the start of the "clearer" part of the year. July is the hottest month, with an average high of 83°F.
It’s comfortable. It’s wet, too. July actually averages about 4 inches of rain, often coming in the form of late-afternoon thunderstorms that roll in over the mountains. These aren't the long, drizzly rains of spring. They're the "everyone off the lake" kind of storms that pass in twenty minutes and leave the air smelling like damp pine.
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Why the Deerfield Fair Weather is a Legend
If you're looking for the best weather in Deerfield NH, look at September.
The humidity drops. The sky becomes that piercing, high-contrast blue that only happens in the fall. The Deerfield Fair, which usually happens around the end of September, is the ultimate weather gamble. I've seen years where it's 85°F and humid, and years where you're wearing a winter coat to look at the prize-winning pumpkins.
- September Highs: Usually around 74°F.
- October Prep: October is actually the wettest month on average (4.44 inches). It’s the rain that brings down the leaves.
- Frost: Expect the first real frost by early to mid-October. If you have a garden, you’re covering those tomatoes by the end of September just to be safe.
Small Details That Matter
Humidity is something people forget about. In July and August, the dew point can hit the mid-60s, making it feel "muggy" even if the thermometer only says 78°F. If you’re hiking around Pawtuckaway, that humidity makes the bugs—especially the black flies in late spring—a lot more aggressive.
Also, the sun doesn't hang around long in the winter. By late December, you’re looking at only about 9 hours of daylight. It changes your mood. It changes how you plan your day. Conversely, June gives you over 15 hours of sun, which is why the town feels so alive in the summer.
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How to Actually Prepare
If you’re moving here or just visiting, forget the "all-season" tires. You need real winter tires. The hills in Deerfield don't care how good your AWD system is when there's an inch of ice under three inches of powder.
Keep a "car kit" that includes a real ice scraper, a warm blanket, and maybe some sand for traction. Honestly, the weather in Deerfield NH is manageable if you respect it. Don't trust the 10-day forecast too much; check the radar on the day of.
Next Steps for Staying Weather-Ready:
- Track the Dew Point: In the summer, look at the dew point rather than just the temp to plan your outdoor chores. Anything over 60°F is going to feel sticky.
- Seal Your Windows by October: Don't wait for the first "Nor'easter" to find out where the drafts are.
- Watch the Pawtuckaway Water Levels: Heavy spring rains (late April/May) can cause local trail closures, so check the state park alerts before heading out.