Walton Ranger Station Historic District · Photo: National Park Service inventory · Public domainHardly any U.S. towns see fresher July days than Essex
The coldest hours of a January night bottom out at 16° on average. Winter nights are cold: in January they are colder than in 82% of U.S. towns. Compared with 1901–2000, the average now sits 1.7° higher. The frost-free window for a garden runs roughly May 9 to October 1.
A year in Essex at a glance
Each month’s typical high and low, and what it brings.
What stands out about Essex’s climate
Compared with towns across the U.S., with Essex’s place in Montana beside it.
What a year in Essex feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 141 frost-free days a year
In half of years the last 32° night comes by May 9 and the first by October 1. Frost and day counts come from Hungry Horse Dam, MT, 19 miles away.
The 2023 USDA map puts Essex’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −18°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 36 inches of rain a year
November is the wettest month and August the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Essex
96% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from September through June.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Hungry Horse Dam, MT.
Living with Essex’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
141 frost-free days in zone 5a. The last frost comes by May 9 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 1.
Months with highs of 62–84° and lows of 40° or more: June, July and August. 0.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Essex from natural hazards, avalanches are the largest share (78%); heat waves, cold waves, winter storms and ice storms together are 4%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Essex and similar climates
TownRatings has no climate map of the towns around Essex yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Essex averaged 1.7° warmer than the 1900s. The biggest change is in January (+4.9°).
A bigger shift than in 73% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Essex compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Essex’s place among Montana’s.
Essex weather by month
Highs, lows and precipitation from NOAA’s grid at Essex’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 31° | 16° | 4.3" | 14° – 30° |
| February | 33° | 16° | 2.9" | 8° – 33° |
| March | 41° | 22° | 2.9" | 22° – 38° |
| April | 50° | 28° | 2.7" | 34° – 46° |
| May | 60° | 35° | 2.8" | 42° – 53° |
| June | 67° | 42° | 3.7" | 52° – 62° |
| July | 78° | 46° | 1.3" | 52° – 70° |
| August | 77° | 45° | 1.2" | 56° – 64° |
| September | 66° | 38° | 2.1" | 48° – 57° |
| October | 51° | 30° | 3.3" | 34° – 47° |
| November | 38° | 23° | 4.6" | 23° – 39° |
| December | 31° | 17° | 3.7" | 15° – 29° |
| Year | 52° | 30° | 35.5" |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 8° to 33°. August is the most reliable, staying within 8°.
Where Essex’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Essex’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Hungry Horse Dam, MT, 19 miles from the town’s center, 700 ft lower; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Essex’s climate
What is the weather like in Essex?
A typical July afternoon reaches 78°, a January night drops to 16°. Colder January nights than 82% of U.S. towns; cooler July afternoons than 96% of U.S. towns.
How cold does it get in Essex in winter?
February nights average 16°. About 169 nights a year reach 32° or below and 10 reach 0° or below. In the coldest February of the last 30 years the month averaged 8°.
How hot does it get in Essex?
July, with a typical high of 78° and a low of 46°. About 16 days a year reach 90° (Hungry Horse Dam, MT).
When is the first and last frost in Essex?
In half of years the last spring frost (32°) comes by May 9 and the first fall frost by October 1, about 141 frost-free days, at Hungry Horse Dam, MT.
What growing zone is Essex in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −18°.
What is the best time of year to visit Essex?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July and August. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Essex getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 73% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Essex.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.