Climate Comfort Score
49/100
Moderate
NOAA 1991–2020 normals 45°F annual avg Public-domain federal data
Roy, MT Climate
Pulled from NOAA NCEI 1991–2020 normals →: average temperature, precipitation, and comfort score
- 45°F
- Avg annual temp
- 49/100
- Comfort score
- 13.3"
- Annual precip
- 133d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for Roy
Roy, Montana averages 45°F a year and scores 49/100 on the comfort index - moderate, milder than 18% of U.S. cities.
- 45°F
- yearly average temperature, NOAA normal
- 49/100
- comfort score, milder than 18% of U.S. cities
- 13.3"
- annual precipitation · 36" snow
- 133 days
- frost-free growing season
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
45°F (7°C)
Avg High
59°F
Avg Low
32°F
Annual Precip
13.3"
Annual Snow
36.3"
Comfort Score
49/100
Moderate
Avg Annual Temperature
45°F
30-year mean (NOAA NCEI)
Annual Precipitation
13.3"
Plus 36.3" of snow
Comfort score vs national 100-point ceiling (Roy) 49.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Moderate for the Roy area.
How Roy compares to every U.S. city
Roy's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
49 Top 82% higher than 18% of 6,915 US cities
Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Warming context for Roy
MethodologyRoy's NOAA 1991-2020 normal sits inside a longer story: U.S. land temperatures have been tracking (and drifting from) the global mean since 1900, and the chart below shows that spread, with the most recent decade running warmer than the 30-year mean.
- United States land mean (NOAA NCEI) +0.11 °C/decade
- Global anomaly (NASA GISTEMP) +0.11 °C/decade
- Paris Agreement thresholds 1.5°C / 2.0°C
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 34°F (1°C) | 10°F (-12°C) | 22°F (-5°C) | 0.5" | 7.7" | 29.3 | 0.0 |
| February | 37°F (3°C) | 13°F (-10°C) | 25°F (-4°C) | 0.4" | 4.7" | 26.1 | 0.0 |
| March | 48°F (9°C) | 22°F (-6°C) | 35°F (2°C) | 0.5" | 6.8" | 26.1 | 0.0 |
| April | 58°F (14°C) | 30°F (-1°C) | 44°F (7°C) | 1.3" | 2.6" | 15.9 | 0.0 |
| May | 68°F (20°C) | 40°F (4°C) | 54°F (12°C) | 2.5" | 0.6" | 5.7 | 0.1 |
| June | 76°F (25°C) | 48°F (9°C) | 62°F (17°C) | 2.6" | 0.0" | 0.1 | 1.5 |
| July | 86°F (30°C) | 54°F (12°C) | 70°F (21°C) | 1.7" | 0.0" | 0.0 | 9.4 |
| August | 86°F (30°C) | 53°F (12°C) | 69°F (21°C) | 1.3" | 0.0" | 0.1 | 12.5 |
| September | 76°F (24°C) | 43°F (6°C) | 59°F (15°C) | 0.9" | 0.0" | 3.0 | 2.8 |
| October | 60°F (16°C) | 32°F (0°C) | 46°F (8°C) | 0.7" | 1.9" | 14.8 | 0.1 |
| November | 46°F (8°C) | 21°F (-6°C) | 33°F (1°C) | 0.5" | 5.5" | 26.1 | 0.0 |
| December | 36°F (2°C) | 12°F (-11°C) | 24°F (-4°C) | 0.4" | 6.5" | 29.6 | 0.0 |
Monthly Precipitation
Average monthly rainfall and snowfall
January 0.5"
Snow: 7.7"
4.0 days with precipitation
February 0.4"
Snow: 4.7"
3.1 days with precipitation
March 0.5"
Snow: 6.8"
4.7 days with precipitation
April 1.3"
Snow: 2.6"
5.5 days with precipitation
May 2.5"
Snow: 0.6"
8.5 days with precipitation
June 2.6"
10.1 days with precipitation
July 1.7"
8.3 days with precipitation
August 1.3"
5.2 days with precipitation
September 0.9"
5.0 days with precipitation
October 0.7"
Snow: 1.9"
4.3 days with precipitation
November 0.5"
Snow: 5.5"
3.8 days with precipitation
December 0.4"
Snow: 6.5"
3.0 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
September 24
50% probability date
Last Spring Freeze
May 14
50% probability date
Growing Season
133 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,566
Higher = more heating needed
Cooling Degree Days
449
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
What Roy's climate means for you
Roy runs 45°F a year - peaking in July, coldest in January.
- Gardeners get about 133 frost-free days, with the last spring freeze near May 14 - plan the planting calendar around it, not the regional average.
- Energy bills track 7,566 heating and 449 cooling degree days a year, higher means the furnace or AC runs more.
- Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings
These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.
Climate Guides
Climate Insight: Roy, MT
Based on station USC00247228 feeding NOAA's 1991–2020 climate normals, Roy, Montana averages 45°F a year, ranging from a mean daily high of 59°F to a mean daily low of 32°F. July is typically the warmest month of the year, while January is the coldest. Because these figures are thirty-year averages rather than any single year's readings, they describe the typical month, not a forecast for it.
Roy averages 13.3 inches of precipitation a year, with 36.3 inches typically falling as snow, and that matters as much to daily life here as temperature does. The frost-free season averages 133 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near May 14 and the first fall freeze near September 24. As for energy demand, 7,566 heating degree days and 449 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Roy scores 49/100 (Moderate), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows, shoulder seasons for mild highs and lows, peak summer for July-driven heat, or deep winter for January-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.
Frequently Asked Questions
What is the average temperature in Roy, MT? ▼
The average annual temperature in Roy, Montana is 45°F. The warmest month averages 86°F (30°C) and the coldest averages 10°F (-12°C).
How much rain does Roy get? ▼
Roy receives 13.3 inches of precipitation annually, including 36.3 inches of snow. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Roy? ▼
Roy has a climate comfort score of 49/100 (Moderate), milder than 18% of U.S. cities in the PlainClimate database.
When is the growing season in Roy? ▼
Roy has approximately 133 frost-free days per year, with the last spring freeze around May 14 and the first fall freeze around September 24.
How much energy does heating and cooling require in Roy? ▼
Roy has 7,566 heating degree days and 449 cooling degree days annually, a heating-dominated climate. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this Roy climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USC00247228 near Roy.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00247228. For informational purposes only.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial
Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.