Discover the best time of year, based on historical climate, temperature, and precipitation.
The best weather in Mount Vernon is from July, August, September. — consistent weather climate
🌥Mild
| Score | 5 | 8 | 23 | 42 | 71 | 80 | 93 | 89 | 81 | 48 | 6 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Climate | Cold | Cold | Cold | Cold | Mild | Mild | Pleasant | Pleasant | Mild | Cold | Cold | Cold |
| Temperature | 2–8°C | 2–8°C | 3–11°C | 4–14°C | 8–17°C | 11–21°C | 13–24°C | 13–24°C | 11–21°C | 8–15°C | 4–9°C | 2–7°C |
| Feels like | -1–5°C | -2–5°C | -1–8°C | 2–11°C | 6–16°C | 10–21°C | 12–25°C | 13–25°C | 11–21°C | 6–14°C | 0–7°C | -2–4°C |
| Precipitation | 186mm 24 days | 150mm 22 days | 116mm 20 days | 105mm 18 days | 92mm 15 days | 71mm 13 days | 19mm 5 days | 38mm 6 days | 72mm 9 days | 147mm 17 days | 203mm 21 days | 204mm 23 days |
| Sunshine | 2.3h ☀︎ 26% | 3.3h ☀︎ 33% | 5.6h ☀︎ 47% | 7.7h ☀︎ 56% | 8.4h ☀︎ 55% | 10.2h ☀︎ 64% | 12.9h ☀︎ 83% | 11.1h ☀︎ 78% | 8.9h ☀︎ 71% | 5.5h ☀︎ 51% | 3.2h ☀︎ 34% | 2.1h ☀︎ 25% |
| Wind | SE · 18 km/h | SE · 15 km/h | SE · 15 km/h | S · 16 km/h | SW · 14 km/h | SW · 13 km/h | SW · 11 km/h | SW · 11 km/h | SW · 13 km/h | SE · 15 km/h | SE · 17 km/h | SE · 17 km/h |
| Humidity (%) | 82% | 83% | 79% | 76% | 77% | 76% | 72% | 76% | 79% | 84% | 83% | 84% |
| Day length | 8.8h | 10.2h | 11.9h | 13.7h | 15.2h | 16.0h | 15.6h | 14.3h | 12.6h | 10.8h | 9.2h | 8.4h |
George Washington's historic estate marks July 4th with a naturalization ceremony, military tributes, and fireworks over…
The estate is decorated in 18th-century holiday style, with candlelight evening tours and seasonal storytelling. Winter…
While standard travel wisdom steers visitors into the congested heat of July or the muddy flower fields of April, September is Mount Vernon's undisputed masterstroke—delivering golden valley warmth without the gridlock.
Strung along the broad sweep of the Skagit River, Mount Vernon is an agricultural powerhouse disguised as a quiet transit node between Seattle and the Canadian border. Most drivers see it as an exit off the interstate or a quick stop at Skagit Station, but the town is the beating heart of the fertile Skagit Valley, framed by distant Cascade peaks and crisscrossed by flat, winding farm roads. It is a place defined entirely by what grows in the dirt and what blows in off the Salish Sea, which means its calendar swings dramatically from sodden grey hibernation to dazzling, sun-drenched abundance.
A standard weather chart tells you to visit in July, point to the unbroken sunshine, and call it a day. That is the consensus view, and it is mistaken. September is the true peak of Mount Vernon, taking every virtue of high summer and stripping away the friction that makes July exhausting.
By September, the oppressive midsummer rush evaporates, yet the days hold onto an effortless, dry warmth. Afternoon temperatures sit comfortably in the low twenties, the air feels crisp rather than heavy, and the relentless glare of July softens into long, amber light that spreads over the pastures of the Skagit Valley. You can drive the backroads without trailing a caravan of campers, stroll the Skagit Riverwalk in peace, and look out from Little Mountain Park across the flats without jostling through a packed observation deck.
Everything in town operates with quiet generosity in September. The farm stands are groaning with late-season harvests, the riverside breezes take the edge off the late-day sun, and the town exhales. It is the rare window where you get quintessential Pacific Northwest clarity without paying for it in lost hours and crowded streets.
July is the weather enthusiast's dream and the crowd-weary traveler's compromise. It is statistically the driest and brightest stretch of the year, bringing weeks of unbroken blue skies and temperatures that settle into a genuine, balmy heat. If your only metric is guaranteed sun, July delivers.
The cost, however, is that everyone else had the same idea. July draws the highest visitor density of the year to Mount Vernon and the surrounding county. Traffic snarls along the river crossings, parking near the downtown core requires patience, and the bucolic calm of the valley gives way to peak-season bustle. It is vibrant and alive, but it requires active planning rather than spontaneous wandering.
August begins the subtle shift downward. The heat lingers—often matching July's peak apparent warmth—and the days remain generously long, but the crowd pressure eases slightly. It is an expansive, lazy month, ideal for lingering on the banks of the Skagit River until dusk, provided you do not mind dry, dusty country lanes and the persistent hum of peak-summer activity.
April is the month Mount Vernon is most famous for, thanks to the Skagit Valley Tulip Festival, and it is also the month most likely to disappoint the unprepared. Visitors arrive anticipating warm spring wandering, only to step into chilly winds and persistent, low-slung drizzle that turns the furrows into thick mud. The temperatures struggle to break into the low teens, and you will spend far more time huddled in waterproof gear than soaking up ambient spring warmth.
Despite the dreary chill, April sees a massive influx of visitors. Downtown fills to the brim, and country roads become slow-moving corridors of tour buses and passenger cars. If you come for the spectacle of millions of colored bulbs tiling the valley floor, come dressed for a cold maritime spring and steel yourself for the congestion.
May is the savvier alternative for spring travel. The festival crowds retreat, the tulip blooms yield to fresh greenery, and the valley shakes off its chill. Temperatures rise noticeably, rain becomes lighter and less frequent, and the agricultural community returns to its authentic rhythm. It is green, fresh, and refreshingly quiet.
Winter in Mount Vernon is not for the faint of heart. Starting in October, Pacific storm tracks lock in, driving relentless moisture into the valley. November and December are the wettest, darkest stretches of the year, dumping immense volumes of water across the river basin while daytime temperatures hover uncomfortably in single digits. The damp cold penetrates thick layers, the daylight hours shrink to brief windows, and gray cloud decks smother the Cascades.
Yet December contains the most jarring anomaly on the calendar: visitor numbers surge right back to peak-summer levels. It is a striking contradiction to see midsummer crowd numbers colliding with the worst, wettest weather the region has to offer. Travelers brave bone-chilling air and near-constant rain, filling the town during the holiday period even as the climate conditions hit bottom.
By January and February, the holiday anomaly breaks and the city settles into deep, quiet solitude. The rain continues in steady, unrelenting spells, but the crowds vanish completely. If you visit in midwinter, you come for moody river views from the Skagit Riverwalk, hot coffee, and total isolation, not for outdoor recreation.