Hotel Rietmann · Photo: Ian Poellet · CC BY-SA 4.0Troy’s winters are milder but snowier than most of the U.S.
A typical July afternoon reaches 84°, a January night drops to 25°, and about 51 inches of snow falls in a normal winter.
A year in Troy at a glance
Each month’s typical high and low, and what it brings.
What stands out about Troy’s climate
Compared with towns across the U.S., with Troy’s place in Idaho beside it.
What a year in Troy feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze is possible in every month
About 139 nights a year fall to 32° or below, and 2 to 0° or below. Frost and day counts come from NOAA’s station at Moscow U Of I, ID, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Troy’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −1°. 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 51 inches of snow a winter
Snow, measured at Moscow U Of I, ID, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 30 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 136 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Troy
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 Moscow U Of I, ID.
Living with Troy’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 6b, and frost can come in any month. The longest frost-free stretch in half of years is about 85 days.
Months with highs of 62–84° and lows of 40° or more: May, June, July and September. 0.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Troy from natural hazards, river flooding is the largest share (47%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Troy and similar climates
TownRatings has no climate map of the towns around Troy yet.
Climates most like Troy’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 |
|---|---|---|---|---|
| Troy, ID | 25° | 84° | 30" | 51" |
| Monroe, MI | 21° | 83° | 34" | 41" |
| Oregon, OH | 21° | 85° | 33" | 37" |
| Geneseo, NY | 18° | 82° | 34" | 52" |
| Bellevue, PA | 22° | 85° | 40" | 44" |
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 Troy averaged 1.3° warmer than the 1900s. The biggest change is in January (+3.8°).
A smaller shift than in 56% 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 Troy compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Troy’s place among Idaho’s.
Troy weather by month
Highs, lows and precipitation from NOAA’s grid at Troy’s center; snow, wet days and snow on the ground from Moscow U Of I, ID. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 25° | 3.9" | 14.5" | 16 | 16 | 22° – 37° |
| February | 42° | 26° | 3.2" | 8.6" | 14 | 9 | 25° – 41° |
| March | 50° | 30° | 3.1" | 4.9" | 16 | 3 | 33° – 46° |
| April | 57° | 34° | 2.7" | 1.0" | 13 | 0 | 40° – 51° |
| May | 66° | 41° | 2.6" | 0.2" | 11 | 0 | 49° – 59° |
| June | 72° | 46° | 1.9" | 0.0" | 9 | 0 | 56° – 66° |
| July | 84° | 49° | 0.7" | 0.0" | 4 | 0 | 59° – 71° |
| August | 84° | 49° | 0.6" | 0.0" | 4 | 0 | 62° – 70° |
| September | 75° | 43° | 1.0" | 0.0" | 6 | 0 | 55° – 64° |
| October | 59° | 35° | 2.4" | 0.2" | 11 | 0 | 41° – 54° |
| November | 45° | 30° | 4.0" | 6.0" | 16 | 4 | 29° – 44° |
| December | 37° | 25° | 4.2" | 15.5" | 16 | 14 | 25° – 35° |
| Year | 59° | 36° | 30.2" | 50.9" | 136 | 46 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 25° to 41°. August is the most reliable, staying within 8°.
Where Troy’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 Troy’s center.
- Snow: Moscow U Of I, ID.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Moscow U Of I, ID, 9 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 Troy’s climate
What is the weather like in Troy?
A typical July afternoon reaches 84°, a January night drops to 25°, and about 51 inches of snow falls in a normal winter. Milder January nights than 63% of U.S. towns; cooler July afternoons than 64% of U.S. towns.
How cold does it get in Troy in winter?
December nights average 25°. About 139 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 25°.
How much snow does Troy get?
About 51 inches in a normal winter at Moscow U Of I, ID, most of it in January and December, with snow on the ground about 46 days a year.
How hot does it get in Troy?
July, with a typical high of 84° and a low of 49°. About 23 days a year reach 90° (Moscow U Of I, ID).
When is the first and last frost in Troy?
There is no reliable frost-free season: at Moscow U Of I, ID, every month has nights at 32° or below, about 139 a year. In half of years the longest stretch without a freeze is about 85 days.
What growing zone is Troy in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −1°.
What is the best time of year to visit Troy?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Troy getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 56% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Troy.
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.