Charles A. Broadwater House · Photo: Jon Roanhaus · CC BY-SA 4.0Dry weather: only 14 inches of rain and melted snow a year in Helena West Side, less than in 94% of U.S. towns
The warmest part of a July day comes in at 84° on average. June is the wettest month here, with about 5.6 times the rain of January. In January, nights here are colder than in 87% of U.S. towns. Central heating does most of its work from October to April, in months below 50° on average.
A year in Helena West Side at a glance
Each month’s typical high and low, and what it brings.
What stands out about Helena West Side’s climate
Compared with towns across the U.S., with Helena West Side’s place in Montana beside it.
What a year in Helena West Side feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 142 frost-free days a year
In half of years the last 32° night comes by May 9 and the first by September 30. Frost and day counts come from NOAA’s station at Helena Rgnl Airport, 7 miles from the town’s center, 460 ft lower.
The 2023 USDA map puts Helena West Side’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −21°. 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 37 inches of snow a winter
Snow, measured at Helena Rgnl Airport, falls mostly in December. Precipitation (rain plus melted snow) adds up to 14 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 91 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Helena West Side
95% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Helena Rgnl Airport.
Living with Helena West Side’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
142 frost-free days in zone 4b. 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 Sep 30.
Months with highs of 62–84° and lows of 40° or more: June, August and September. 46 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Helena West Side from natural hazards, avalanches are the largest share (36%); heat waves, cold waves, winter storms and ice storms together are 34%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Helena West Side and its neighbors
Every town next door is within a degree of Helena West Side in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Helena West Side’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Helena West Side, MT | 14° | 84° | 14" | 37" |
| Cody, WY | 14° | 85° | 11" | 45" |
| Taos, NM | 11° | 84° | 13" | 28" |
| Cimarron Hills, CO | 18° | 85° | 17" | 33" |
| Rapid City, SD | 14° | 86° | 19" | 36" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Helena West Side averaged 1.3° warmer than the 1900s. The biggest change is in January (+4.3°).
A smaller shift than in 51% 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 Helena West Side compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Helena West Side’s place among Montana’s.
Helena West Side weather by month
Highs, lows and precipitation from NOAA’s grid at Helena West Side’s center; snow, wet days and snow on the ground from Helena Rgnl Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 34° | 14° | 0.4" | 6.6" | 7 | 18 | 14° – 32° |
| February | 37° | 16° | 0.5" | 6.6" | 7 | 11 | 10° – 36° |
| March | 47° | 23° | 0.8" | 4.6" | 7 | 5 | 24° – 43° |
| April | 55° | 30° | 1.4" | 2.9" | 9 | 1 | 37° – 48° |
| May | 65° | 38° | 2.2" | 0.1" | 11 | 0 | 46° – 56° |
| June | 73° | 45° | 2.5" | 0.0" | 12 | 0 | 54° – 66° |
| July | 84° | 51° | 1.2" | 0.0" | 8 | 0 | 57° – 74° |
| August | 83° | 49° | 1.1" | 0.3" | 6 | 0 | 60° – 70° |
| September | 72° | 41° | 1.2" | 0.2" | 6 | 0 | 52° – 61° |
| October | 57° | 31° | 1.1" | 2.8" | 7 | 2 | 37° – 51° |
| November | 42° | 22° | 0.8" | 5.4" | 7 | 6 | 24° – 41° |
| December | 33° | 15° | 0.5" | 7.7" | 7 | 14 | 14° – 30° |
| Year | 57° | 31° | 13.6" | 37.2" | 91 | 57 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 10° to 36°. September is the most reliable, staying within 9°.
Where Helena West Side’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 Helena West Side’s center.
- Snow: Helena Rgnl Airport.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Helena Rgnl Airport, 7 miles from the town’s center, 460 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- 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 Helena West Side’s climate
What is the weather like in Helena West Side?
A typical July afternoon reaches 84°, a January night drops to 14°, and about 37 inches of snow falls in a normal winter. Colder January nights than 87% of U.S. towns; cooler July afternoons than 59% of U.S. towns.
How cold does it get in Helena West Side in winter?
January nights average 14°. About 170 nights a year reach 32° or below and 17 reach 0° or below. In the coldest January of the last 30 years the month averaged 14°.
How much snow does Helena West Side get?
About 37 inches in a normal winter at Helena Rgnl Airport, most of it in December, with snow on the ground about 57 days a year.
How hot does it get in Helena West Side?
July, with a typical high of 84° and a low of 51°. About 27 days a year reach 90° and 1 reach 100° (Helena Rgnl Airport).
When is the first and last frost in Helena West Side?
In half of years the last spring frost (32°) comes by May 9 and the first fall frost by September 30, about 142 frost-free days, at Helena Rgnl Airport.
What growing zone is Helena West Side in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −21°.
What is the best time of year to visit Helena West Side?
By one simple rule (highs of 62–84° and lows of 40° or more), June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Helena West Side getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 51% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Helena West Side.
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.