Photo: Travellers & Tinkers · CC BY-SA 4.0Hardly any U.S. towns see fresher July days than Mullan
In January the night’s low is typically 23°. Compared with 1901–2000, the average now sits 1.2° higher. The frost-free window for a garden runs roughly May 12 to September 30.
A year in Mullan at a glance
Each month’s typical high and low, and what it brings.
What stands out about Mullan’s climate
Compared with towns across the U.S., with Mullan’s place in Idaho beside it.
What a year in Mullan feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 138 frost-free days a year
In half of years the last 32° night comes by May 12 and the first by September 30. Frost and day counts come from NOAA’s station at Mullan, ID, 0.7 miles from the town’s center, 240 ft lower.
The 2023 USDA map puts Mullan’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −4°. 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 76 inches of snow a winter
Snow, measured at Wallace, ID, falls mostly in December. Precipitation (rain plus melted snow) adds up to 42 inches a year; November is the wettest month and July the driest. Rain or snow falls on about 151 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Mullan
97% 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 Mullan, ID.
Living with Mullan’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
138 frost-free days in zone 6b. The last frost comes by May 12 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, July, August and September.
Parks & trails →Of the yearly building losses FEMA expects in Mullan from natural hazards, river flooding is the largest share (59%); heat waves, cold waves, winter storms and ice storms together are 3%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Mullan and similar climates
TownRatings has no climate map of the towns around Mullan yet.
Climates most like Mullan’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 |
|---|---|---|---|---|
| Mullan, ID | 23° | 79° | 42" | 76" |
| Ashtabula, OH | 22° | 80° | 41" | 90" |
| Dunkirk, NY | 20° | 80° | 39" | 76" |
| Frostburg, MD | 20° | 82° | 44" | 72" |
| Beckley, WV | 23° | 81° | 44" | 56" |
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 Mullan averaged 1.2° warmer than the 1900s. The biggest change is in January (+3.8°).
A smaller shift than in 65% 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 Mullan compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Mullan’s place among Idaho’s.
Mullan weather by month
Highs, lows and precipitation from NOAA’s grid at Mullan’s center; snow, wet days and snow on the ground from Wallace, ID. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 32° | 23° | 5.0" | 19.7" | 17 | 21° – 32° |
| February | 36° | 23° | 4.3" | 13.3" | 14 | 19° – 36° |
| March | 43° | 27° | 4.4" | 11.5" | 17 | 28° – 42° |
| April | 51° | 31° | 3.6" | 1.3" | 15 | 36° – 48° |
| May | 61° | 38° | 3.2" | 0.2" | 12 | 44° – 55° |
| June | 68° | 44° | 3.0" | 0.0" | 12 | 52° – 64° |
| July | 79° | 50° | 1.0" | 0.0" | 7 | 54° – 70° |
| August | 78° | 49° | 1.1" | 0.0" | 5 | 58° – 67° |
| September | 68° | 42° | 1.7" | 0.0" | 7 | 51° – 61° |
| October | 52° | 34° | 3.9" | 0.4" | 12 | 37° – 50° |
| November | 38° | 27° | 5.4" | 6.5" | 18 | 26° – 38° |
| December | 31° | 22° | 5.2" | 22.7" | 16 | 21° – 31° |
| Year | 53° | 34° | 41.8" | 75.6" | 151 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 19° to 36°. August is the most reliable, staying within 9°.
Where Mullan’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 Mullan’s center.
- Snow: Wallace, ID.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Mullan, ID, 0.7 miles from the town’s center, 240 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 Mullan’s climate
What is the weather like in Mullan?
A typical July afternoon reaches 79°, a January night drops to 23°, and about 76 inches of snow falls in a normal winter. Milder January nights than 54% of U.S. towns; cooler July afternoons than 95% of U.S. towns.
How cold does it get in Mullan in winter?
December nights average 22°. About 162 nights a year reach 32° or below and 2 reach 0° or below. In the coldest December of the last 30 years the month averaged 21°.
How much snow does Mullan get?
About 76 inches in a normal winter at Wallace, ID, most of it in December.
How hot does it get in Mullan?
July, with a typical high of 79° and a low of 50°. About 10 days a year reach 90° (Mullan, ID).
When is the first and last frost in Mullan?
In half of years the last spring frost (32°) comes by May 12 and the first fall frost by September 30, about 138 frost-free days, at Mullan, ID.
What growing zone is Mullan in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −4°.
What is the best time of year to visit Mullan?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Mullan getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 65% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Mullan.
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.