Hanna, WY climate
Hanna has cold, snowy winters and pleasant summers, with very little rain. A typical July afternoon reaches 83°, a January night drops to 13°, and about 93 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Hanna feels like
Winter
Spring
Summer
Fall
Hanna weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 33° | 13° | 0.6" | 9.0" | 5 | 15° – 30° |
| February | 35° | 14° | 0.7" | 15.1" | 5 | 18° – 30° |
| March | 45° | 22° | 0.9" | 13.2" | 6 | 26° – 40° |
| April | 53° | 28° | 1.4" | 17.0" | 8 | 34° – 46° |
| May | 63° | 36° | 1.8" | 5.1" | 7 | 44° – 54° |
| June | 75° | 44° | 1.2" | 0 | 4 | 54° – 64° |
| July | 83° | 51° | 1.0" | 0 | 4 | 61° – 71° |
| August | 81° | 49° | 0.8" | 0 | 4 | 60° – 68° |
| September | 71° | 40° | 1.1" | 0.4" | 4 | 51° – 60° |
| October | 57° | 30° | 1.2" | 11.6" | 5 | 36° – 51° |
| November | 43° | 21° | 0.8" | 9.4" | 5 | 20° – 39° |
| December | 33° | 13° | 0.7" | 12.5" | 6 | 17° – 28° |
| Year | 56° | 30° | 12.0" | 93.3" | 64 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Hanna
Hanna gets 12 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 64 days a year.
About 108 frost-free days a year
In half of years the last 32° night comes by May 28 and the first one by September 13. That leaves about 108 frost-free days for gardens, shorter than 99% of U.S. towns.
Heating and cooling a home in Hanna
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Hanna, 98% of that work is heating and 2% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Hanna compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Hanna averaged 1.8° warmer than the 1900s. The biggest change is in March (+4.3°). The shift is larger than in 89% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Hanna’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 20° to 39°. August is the most reliable, staying within 8°.
Common questions about Hanna’s climate
What is the coldest month in Hanna?
January, with a typical high of 33° and a low of 13°.
What is the hottest month in Hanna?
July, with a typical high of 83° and a low of 51°. About 3 days a year reach 90°.
How much snow does Hanna get?
About 93 inches in a normal winter, most of it in April.
When is the first frost in Hanna?
In half of years the first 32° night comes by September 13, and the last spring frost by May 28.
What is the rainiest month in Hanna?
May, with 1.8 inches of rain and melted snow. The year totals 12 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Hanna itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Elk Mtn, WY (15 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.