Lyman’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 82°, a January night drops to 9°, and about 64 inches of snow falls in a normal winter.
A year in Lyman at a glance
Each month’s typical high and low, and what it brings.
What stands out about Lyman’s climate
Compared with towns across the U.S., with Lyman’s place in Wyoming beside it.
What a year in Lyman feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 84 frost-free days a year
In half of years the last 32° night comes by June 14 and the first by September 9. Frost and day counts come from NOAA’s station at Mtn View, WY, 5 miles from the town’s center, at about the same height.
The 2023 USDA map puts Lyman’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −17°. 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 64 inches of snow a winter
Snow, measured at Mtn View, WY, falls mostly in January, February, March, November and December. Precipitation (rain plus melted snow) adds up to 10 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 82 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Lyman
99% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from September 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 Mtn View, WY.
Living with Lyman’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
84 frost-free days in zone 5a. The last frost comes by Jun 14 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 9.
Months with highs of 62–84° and lows of 40° or more: June, July and August. 0.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Lyman from natural hazards, river flooding is the largest share (56%); heat waves, cold waves, winter storms and ice storms together are 12%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Lyman and similar climates
TownRatings has no climate map of the towns around Lyman yet.
Climates most like Lyman’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 |
|---|---|---|---|---|
| Lyman, WY | 9° | 82° | 10" | 64" |
| Rexburg, ID | 12° | 84° | 13" | 70" |
| Great Falls, MT | 13° | 84° | 13" | 66" |
| Watford City, ND | 4° | 84° | 16" | 50" |
| Salida, CO | 10° | 85° | 8" | 37" |
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 Lyman averaged 1.0° warmer than the 1900s. The biggest change is in March (+3.1°).
A smaller shift than in 75% 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 Lyman compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Lyman’s place among Wyoming’s.
Lyman weather by month
Highs, lows and precipitation from NOAA’s grid at Lyman’s center; snow, wet days and snow on the ground from Mtn View, WY. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 31° | 9° | 0.5" | 8.9" | 6 | 22 | 12° – 30° |
| February | 34° | 11° | 0.5" | 9.0" | 6 | 17 | 16° – 31° |
| March | 44° | 20° | 0.6" | 9.4" | 7 | 8 | 24° – 38° |
| April | 53° | 25° | 1.0" | 7.5" | 8 | 2 | 33° – 46° |
| May | 64° | 34° | 1.4" | 3.0" | 9 | 0 | 43° – 54° |
| June | 74° | 42° | 0.9" | 0.2" | 6 | 0 | 52° – 63° |
| July | 82° | 48° | 0.9" | 0.0" | 7 | 0 | 58° – 70° |
| August | 80° | 46° | 0.9" | 0.0" | 8 | 0 | 59° – 66° |
| September | 71° | 38° | 1.0" | 1.0" | 7 | 0 | 51° – 59° |
| October | 58° | 28° | 1.0" | 5.6" | 7 | 2 | 35° – 48° |
| November | 42° | 18° | 0.6" | 9.7" | 6 | 10 | 20° – 36° |
| December | 31° | 9° | 0.5" | 9.5" | 7 | 21 | 15° – 29° |
| Year | 55° | 27° | 9.8" | 63.8" | 82 | 82 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 12° to 30°. August is the most reliable, staying within 7°.
Where Lyman’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 Lyman’s center.
- Snow: Mtn View, WY.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Mtn View, WY, 5 miles from the town’s center, at about the same height; 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 Lyman’s climate
What is the weather like in Lyman?
A typical July afternoon reaches 82°, a January night drops to 9°, and about 64 inches of snow falls in a normal winter. Colder January nights than 94% of U.S. towns; cooler July afternoons than 77% of U.S. towns.
How cold does it get in Lyman in winter?
January nights average 9°. About 206 nights a year reach 32° or below and 13 reach 0° or below. In the coldest January of the last 30 years the month averaged 12°.
How much snow does Lyman get?
About 64 inches in a normal winter at Mtn View, WY, most of it in January, February, March, November and December, with snow on the ground about 82 days a year.
How hot does it get in Lyman?
July, with a typical high of 82° and a low of 48°. About 1 days a year reach 90° (Mtn View, WY).
When is the first and last frost in Lyman?
In half of years the last spring frost (32°) comes by June 14 and the first fall frost by September 9, about 84 frost-free days, at Mtn View, WY.
What growing zone is Lyman in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −17°.
What is the best time of year to visit Lyman?
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 Lyman getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 75% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Lyman.
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.