Sidney, MT Climate: Temperature & Rain by Month
Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate
30-year climate normals (1991-2020) from Sidney's primary NOAA station, SIDNEY.
The climate verdict for Sidney
Winter sets the terms in Sidney, Montana. A pronounced 55.1°F seasonal swing and heating demand above twice the cooling total frame an annual average of 45°F. At 49/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 18% of scores.
- 45°F
- average temperature, NOAA 1991-2020 normal
- 49/100
- comfort score, above 18% of station-mapped location scores
- 15.5"
- annual precipitation · 30" snow
- 139 days
- frost-free growing season
Sidney: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00247560 · Sidney, MT 45°F mean · 15.5" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 45°F
- RANK-COOL #1,372
- PHOTO-FINISH ≈ Plainview
- PRCP-DRY 15.5"
- SWING-WIDE 55°F
- COMF-LOW 49/100
- LOAD-HEAT 7,770 HDD
- STN-1 USC00247560
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Plainview, SD (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every MT station list.
- Sidney (this station) 45°F
- Cold Durand, WI 45°F
- Hot Osage, IA 45°F
- Near Plainview, SD 45°F
- Near Redig, SD 45°F
Sidney sits in Montana, the #6 coldest U.S. state at 43.4°F statewide annual average - see all 50 coldest states ranked by NOAA normals
Climate Living Index · Sidney
Sidney: 25/100 · grade F
Sidney publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Sidney, not an official NOAA rating. Rankings still use Comfort Score 49/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Snowfall burden | 30.4 inches/year | 38/100 · F |
| Precipitation balance | 15.5 in · 19.5 from 35 in | 30/100 · F |
| Normal heat + freeze calendar | 180 calendar days | 25/100 · F |
| Annual temperature balance | 45.2°F · 22.3° from 67.5°F | 20/100 · F |
| Frost-free season | 139 days/year | 18/100 · F |
Sidney · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Sidney's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 72.0°F
- Coldest month
- 16.9°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Sidney sits across the climate record
Three NOAA fields for Sidney's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 80%
- Among 6,861 stations, Sidney sits in the cooler third of annual means.
- Annual precipitation
- Drier than 81%
- Sidney's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 92%
- Warmest-to-coldest month gap for Sidney is large versus 6,861 complete station-years.
How Sidney compares across U.S. station-mapped locations
Sidney's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
49 18th percentile score exceeds 18% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Sidney's measured station temperature trend
MethodologyAcross 63 complete annual observations from 1950 to 2020, SIDNEY warmed at a fitted rate of 0.31°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Sidney primary station fitted change +0.31 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 27°F (-3°C) | 7°F (-14°C) | 17°F (-8°C) | 0.5" | 7.0" | 30.2 | 0.0 |
| February | 32°F (0°C) | 11°F (-12°C) | 21°F (-6°C) | 0.4" | 5.6" | 27.5 | 0.0 |
| March | 46°F (8°C) | 21°F (-6°C) | 33°F (1°C) | 0.6" | 3.0" | 27.2 | 0.0 |
| April | 61°F (16°C) | 32°F (0°C) | 46°F (8°C) | 1.2" | 1.7" | 16.3 | 0.1 |
| May | 71°F (22°C) | 43°F (6°C) | 57°F (14°C) | 2.4" | 0.7" | 4.4 | 0.7 |
| June | 79°F (26°C) | 52°F (11°C) | 66°F (19°C) | 2.8" | 0.0" | 0.1 | 3.2 |
| July | 87°F (30°C) | 57°F (14°C) | 72°F (22°C) | 2.6" | 0.0" | 0.0 | 11.7 |
| August | 86°F (30°C) | 55°F (13°C) | 71°F (22°C) | 1.3" | 0.0" | 0.0 | 11.0 |
| September | 76°F (24°C) | 46°F (8°C) | 61°F (16°C) | 1.6" | 0.0" | 1.8 | 3.1 |
| October | 59°F (15°C) | 34°F (1°C) | 47°F (8°C) | 1.1" | 1.5" | 13.7 | 0.1 |
| November | 42°F (5°C) | 21°F (-6°C) | 32°F (0°C) | 0.6" | 3.0" | 26.5 | 0.0 |
| December | 31°F (-1°C) | 11°F (-12°C) | 21°F (-6°C) | 0.5" | 7.9" | 30.5 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 89°F around July 30, short of 90°F on every date, while 180 dates carry a normal low at or below freezing, the coldest 6°F near January 9.
The freezing stretch
The normal low stays at or below 32°F into April 16, then returns to freezing around October 20, covering 180 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is June 10, when 38% of years recorded at least a hundredth of an inch. The driest is February 4 at 17%. Summed across the calendar, that is about 85 wet dates a year.
The widest day
August 18 carries the biggest normal gap between afternoon and dawn, 32°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Sidney.
Where Sidney Stands Nationally
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 180 nights a year, more than most ranked stations.
A drier-than-most normal water year — around 16 inches, below what four out of five ranked stations collect.
Sidney earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 7.0"
6.5 days with precipitation
Snow: 5.6"
4.7 days with precipitation
Snow: 3.0"
5.6 days with precipitation
Snow: 1.7"
6.4 days with precipitation
Snow: 0.7"
10.4 days with precipitation
11.3 days with precipitation
8.5 days with precipitation
6.8 days with precipitation
6.7 days with precipitation
Snow: 1.5"
6.7 days with precipitation
Snow: 3.0"
5.2 days with precipitation
Snow: 7.9"
5.7 days with precipitation
Sidney runs a summer-peaked wet season
43% of Sidney's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is June at 2.8", on a wide 55.1°F gap between its warmest and coldest month. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: June, July, May, taking 51% of the annual total between them.
- Driest month: February at 0.4".
- Winter share: 9% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
Sidney is dry, and what does fall arrives gently
Only about 85 days a year record measurable precipitation here, 23% of the calendar, and they carry 15.5" between them. At roughly 0.18 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is June at about 11 wet days; the driest is February at about 5.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Winter brings real snow to Sidney
Sidney averages 30.4 inches of snowfall a year, with December the snowiest month on the normals, spread across roughly 24 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 30.4 inches of depth.
- Days recording measurable snow: about 24 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 20% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
September 27
50% probability date
Last Spring Freeze
May 11
50% probability date
Growing Season
139 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,770
Higher = more heating needed
Cooling Degree Days
593
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside MT closest to Sidney on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (45°F here).
- Albert Lea, MN 45°F · 0.0°F off
- Brillion, WI 45°F · 0.0°F off
- Easton, WA 45°F · 0.0°F off
- Freeville, NY 45°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (15.5" here), excluding temperature-peer places.
- Denio, NV 15.5" · 0.0" off
- Fort Davis, TX 15.5" · 0.0" off
- Kanosh, UT 15.5" · 0.0" off
- Arco, ID 15.5" · 0.0" off
Snow and freeze rhythm
When cold and snow define Sidney
heating led · dry · high swing
Winter and seasonal range jointly define this record. Sidney logs 7,770 heating degree days, more than twice its 593 cooling total, while the typical coldest-to-warmest-month gap reaches 55.1°F. The annual mean therefore compresses two materially different seasons.
Only about 139 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
-
1. Sidney coldest normal
January
Averaging 17°F (-8°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Sidney typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Sidney snow peak
December
Sidney averages 30.4 inches of snow a year, with December the snowiest month on the normals.
Questions about Sidney's climate
How much snow does Sidney get? ▼
How cold does Sidney get in winter? ▼
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Sidney's primary station: SIDNEY (USC00247560). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 3067900). Match rule for Sidney: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Sidney comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.