Sidney, Iowa climate: Normal weather by month, frost dates and records
Sidney's normal year runs from 13°F January nights to 86°F July afternoons, with 33.3 inches of precipitation and 21 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.4°C, January lows of −10°C, July highs of 30°C, 845 mm of precipitation a year.
- NOAA stationSidney (1 mi SSE)
- Station IDUSC00137669
- Location40.74°N 95.64°W
- Elevation1,140 ft (348 m)
- Population1,048
On October 23, the normal high in Sidney is 62°F and the normal low 39°F, and the chance of measurable rain or snow is 22%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Sidney.
- Jan 33° 13°
- Feb 38° 17°
- Mar 51° 28°
- Apr 63° 39°
- May 73° 51°
- Jun 82° 61°
- Jul 86° 65°
- Aug 84° 63°
- Sep 78° 54°
- Oct 65° 42°
- Nov 50° 29°
- Dec 37° 19°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Sidney each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 13°F. The most precipitation falls in May (5.26 in), the least in January (0.77 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 13°F | 22.8°F | 0.77 | 5.0 | 5 | <1 | 30 | 9 h 30 min |
| February | 38°F | 17°F | 27.6°F | 1.03 | 6.3 | 5 | <1 | 25 | 10 h 40 min |
| March | 51°F | 28°F | 39.3°F | 1.85 | 2.3 | 7 | <1 | 21 | 11 h 50 min |
| April | 63°F | 39°F | 50.5°F | 3.15 | 1.2 | 10 | <1 | 7 | 13 h 20 min |
| May | 73°F | 51°F | 61.5°F | 5.26 | 0.0 | 11 | 1 | <1 | 14 h 30 min |
| June | 82°F | 61°F | 71.6°F | 4.81 | 0.0 | 10 | 5 | <1 | 15 h |
| July | 86°F | 65°F | 75.4°F | 4.49 | 0.0 | 9 | 9 | <1 | 14 h 50 min |
| August | 84°F | 63°F | 73.2°F | 3.28 | 0.0 | 8 | 7 | <1 | 13 h 50 min |
| September | 78°F | 54°F | 65.7°F | 3.10 | 0.0 | 7 | 3 | <1 | 12 h 30 min |
| October | 65°F | 42°F | 53.6°F | 2.72 | 0.5 | 7 | <1 | 4 | 11 h 10 min |
| November | 50°F | 29°F | 39.2°F | 1.59 | 1.1 | 6 | <1 | 18 | 10 h |
| December | 37°F | 19°F | 27.9°F | 1.21 | 4.2 | 5 | <1 | 29 | 9 h 20 min |
| Year (annual) | 62°F | 40°F | 50.7°F | 33.26 | 20.6 | 89 | 24 | 134 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −10°C | −5.1°C | 20 mm | 13 cm |
| February | 3°C | −8°C | −2.4°C | 26 mm | 16 cm |
| March | 10°C | −2°C | 4.1°C | 47 mm | 6 cm |
| April | 17°C | 4°C | 10.3°C | 80 mm | 3 cm |
| May | 23°C | 10°C | 16.4°C | 134 mm | 0 cm |
| June | 28°C | 16°C | 22.0°C | 122 mm | 0 cm |
| July | 30°C | 18°C | 24.1°C | 114 mm | 0 cm |
| August | 29°C | 17°C | 22.9°C | 83 mm | 0 cm |
| September | 25°C | 12°C | 18.7°C | 79 mm | 0 cm |
| October | 19°C | 5°C | 12.0°C | 69 mm | 1 cm |
| November | 10°C | −2°C | 4.0°C | 40 mm | 3 cm |
| December | 3°C | −7°C | −2.3°C | 31 mm | 11 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137669; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Sidney?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137669.
When is the last frost in Sidney?
In Sidney, the last spring frost (32°F) comes after April 19 in half of years and after May 2 in one year in ten; the first autumn frost comes before October 19 in half of years and before October 1 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 191 year in 10 after May 2; 9 in 10 after April 5
- First autumn frost, half of years before
- October 191 year in 10 before October 1; 9 in 10 before October 31
NOAA puts the median frost-free season at 182 days, and the season without a hard freeze (28°F) at 203 days.
A hard freeze (28°F) comes after April 9 in half of springs and before October 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Sidney in zone 5b in ZIP code 51652, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Sidney's NOAA station is in zone 6a: the coldest night of a typical year reaches −9°F (26 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Iowa · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00137669; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Sidney?
In a normal year in Sidney, 24 days a year reach 90°F (1 of them 100°F or more), 134 nights fall to 32°F or colder and 89 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 134a normal year
- Days that stay below freezing
- 44high of 32°F or less
- Days with 0.01 inch of precipitation
- 89a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1895) is 109°F, on July 21, 1974; the lowest is −25°F, on December 23, 1989.
The wettest calendar year on that record is 1993, with 51.94 in; the snowiest season is 1972–73, with 54.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00137669; records: ACIS (NOAA Regional Climate Centers), station USC00137669. Records use complete months only; a month missing more than three days is left out.
How sunny is Sidney?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Sidney, 4.3 kWh per square metre a day. July is the sunniest month (84%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.2 |
| February | 74% | 3.1 |
| March | 70% | 3.9 |
| April | 71% | 5.0 |
| May | 73% | 5.8 |
| June | 80% | 6.5 |
| July | 84% | 6.6 |
| August | 82% | 5.7 |
| September | 81% | 4.7 |
| October | 76% | 3.3 |
| November | 75% | 2.4 |
| December | 70% | 1.8 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Sidney need?
A normal year in Sidney brings 6,182 heating degree days, 15% more than the median U.S. place (5,373), and 996 cooling degree days, 10% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,386 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,308 | 0 |
| February | 1,049 | 0 |
| March | 800 | 2 |
| April | 442 | 7 |
| May | 170 | 62 |
| June | 18 | 215 |
| July | 2 | 323 |
| August | 7 | 261 |
| September | 90 | 111 |
| October | 372 | 17 |
| November | 774 | 0 |
| December | 1,150 | 0 |
| Year (annual) | 6,182 | 996 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00137669. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Sidney been warmer than normal lately?
Over 52 complete years from 1950 to 2017, the station's annual mean temperature rose at a fitted 4.6°F per century (+0.26°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Sidney's climate compare?
Sidney is warmer than 119 of the other 131 places with their own NOAA record in Iowa, and wetter than 25. Across the 7,247 U.S. stations with normals, its annual mean of 50.7°F is warmer than 44%.
In the Köppen classification computed from these normals, Sidney is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Sidney share this climate record?
5 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Riverton, IA243 people · 5 mi SE
- Union, NE201 people · 16 mi W
- Randolph, IA183 people · 10 mi NE
- Julian, NE46 people · 19 mi SW
- Anderson, IA28 people · 5 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Sidney's climate
What is the coldest month in Sidney?
January, with a normal high of 33°F and a normal low of 13°F. The warmest is July (86°F by day, 65°F at night).
Does it snow in Sidney?
Yes: 21 inches in a normal year, falling on 12 days with 0.1 inch or more, the most in February (6.3 inches).
What is the rainiest month in Sidney?
May, with 5.26 in of precipitation in a normal year; the driest is January with 0.77 in.
What plant hardiness zone is Sidney in?
The USDA's 2023 map puts Sidney in zone 5b in ZIP code 51652, the nearest ZIP area. By the same method at Sidney's NOAA station, the coldest night of a typical year reaches −9°F (26 years, 1991-2020): zone 6a.
How late can frost come in Sidney?
In half of years the last 32°F night comes after April 19; in one year in ten it comes after May 2. Waiting until May 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Iowa climateThe statewide normals and every place in the state
- Nebraska City, NE13 miles from this station, 51.4°F a year
- Shenandoah, IA15 miles from this station, 51.8°F a year
- Glenwood, IA20 miles from this station, 50.9°F a year
- Tarkio, MO25 miles from this station, 51.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made