Ottawa, Kansas climate: Normal weather by month, frost dates and records
Ottawa's normal year runs from 18°F January nights to 89°F July afternoons, with 39.9 inches of precipitation and 9 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.5°C, January lows of −8°C, July highs of 32°C, 1,012 mm of precipitation a year.
- NOAA stationOttawa
- Station IDUSC00146128
- Location38.61°N 95.28°W
- Elevation905 ft (276 m)
- From the center1 miles
- Population12,733
On October 23, the normal high in Ottawa is 66°F and the normal low 41°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ottawa.
- Jan 40° 18°
- Feb 46° 22°
- Mar 56° 32°
- Apr 66° 42°
- May 75° 53°
- Jun 84° 63°
- Jul 89° 68°
- Aug 88° 65°
- Sep 80° 56°
- Oct 69° 44°
- Nov 55° 32°
- Dec 43° 22°
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 Ottawa each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 18°F. The most precipitation falls in May (5.82 in), the least in January (1.22 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 40°F | 18°F | 29.0°F | 1.22 | 3.2 | 7 | <1 | 27 | 9 h 40 min |
| February | 46°F | 22°F | 33.8°F | 1.57 | 2.1 | 6 | <1 | 22 | 10 h 40 min |
| March | 56°F | 32°F | 43.7°F | 2.29 | 0.7 | 8 | <1 | 14 | 11 h 50 min |
| April | 66°F | 42°F | 53.7°F | 3.79 | 0.0 | 10 | <1 | 4 | 13 h 10 min |
| May | 75°F | 53°F | 64.3°F | 5.82 | 0.0 | 13 | 1 | <1 | 14 h 10 min |
| June | 84°F | 63°F | 73.8°F | 5.55 | 0.0 | 10 | 8 | <1 | 14 h 50 min |
| July | 89°F | 68°F | 78.4°F | 3.75 | 0.0 | 9 | 17 | <1 | 14 h 40 min |
| August | 88°F | 65°F | 76.6°F | 4.63 | 0.0 | 9 | 15 | <1 | 13 h 40 min |
| September | 80°F | 56°F | 68.2°F | 4.05 | 0.0 | 8 | 5 | <1 | 12 h 30 min |
| October | 69°F | 44°F | 56.3°F | 3.08 | 0.1 | 9 | <1 | 3 | 11 h 20 min |
| November | 55°F | 32°F | 43.2°F | 2.39 | 0.5 | 7 | <1 | 15 | 10 h 10 min |
| December | 43°F | 22°F | 32.9°F | 1.71 | 2.6 | 6 | <1 | 25 | 9 h 30 min |
| Year (annual) | 66°F | 43°F | 54.5°F | 39.85 | 9.2 | 102 | 47 | 111 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −8°C | −1.7°C | 31 mm | 8 cm |
| February | 8°C | −6°C | 1.0°C | 40 mm | 5 cm |
| March | 13°C | 0°C | 6.5°C | 58 mm | 2 cm |
| April | 19°C | 5°C | 12.1°C | 96 mm | 0 cm |
| May | 24°C | 12°C | 17.9°C | 148 mm | 0 cm |
| June | 29°C | 17°C | 23.2°C | 141 mm | 0 cm |
| July | 32°C | 20°C | 25.8°C | 95 mm | 0 cm |
| August | 31°C | 18°C | 24.8°C | 118 mm | 0 cm |
| September | 27°C | 13°C | 20.1°C | 103 mm | 0 cm |
| October | 20°C | 7°C | 13.5°C | 78 mm | 0 cm |
| November | 13°C | 0°C | 6.2°C | 61 mm | 1 cm |
| December | 6°C | −5°C | 0.5°C | 43 mm | 7 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00146128; 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 Ottawa?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, September has the fewest days with rain (8).
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 USC00146128.
When is the last frost in Ottawa?
In Ottawa, the last spring frost (32°F) comes after April 18 in half of years and after May 1 in one year in ten; the first autumn frost comes before October 20 in half of years and before October 3 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 181 year in 10 after May 1; 9 in 10 after April 5
- First autumn frost, half of years before
- October 201 year in 10 before October 3; 9 in 10 before November 1
NOAA puts the median frost-free season at 183 days, and the season without a hard freeze (28°F) at 203 days.
A hard freeze (28°F) comes after April 8 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Ottawa in zone 6b in ZIP code 66067, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Ottawa's NOAA station is in zone 6b: the coldest night of a typical year reaches −5°F (27 complete years).
Frost dates for every NOAA station in Kansas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00146128; 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 Ottawa?
In a normal year in Ottawa, 47 days a year reach 90°F (5 of them 100°F or more), 111 nights fall to 32°F or colder and 102 days bring measurable precipitation.
- Days at 90°F or more
- 47a normal year
- Days at 100°F or more
- 5a normal year
- Nights at 32°F or colder
- 111a normal year
- Days that stay below freezing
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 102a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1895) is 118°F, on July 14, 1954; the lowest is −28°F, on February 13, 1905.
The wettest calendar year on that record is 2019, with 64.61 in; the snowiest season is 1959–60, with 62.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00146128; records: ACIS (NOAA Regional Climate Centers), station USC00146128. Records use complete months only; a month missing more than three days is left out.
How sunny is Ottawa?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Ottawa, 4.4 kWh per square metre a day. July is the sunniest month (84%) and March the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.3 |
| February | 72% | 3.1 |
| March | 70% | 4.0 |
| April | 72% | 5.1 |
| May | 74% | 5.8 |
| June | 82% | 6.7 |
| July | 84% | 6.5 |
| August | 83% | 5.8 |
| September | 82% | 4.8 |
| October | 77% | 3.6 |
| November | 76% | 2.6 |
| December | 72% | 2.0 |
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 Ottawa need?
A normal year in Ottawa brings 5,130 heating degree days, 5% fewer than the median U.S. place (5,373), and 1,337 cooling degree days, 47% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,963 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,114 | 0 |
| February | 875 | 0 |
| March | 661 | 2 |
| April | 351 | 13 |
| May | 115 | 92 |
| June | 7 | 271 |
| July | 1 | 417 |
| August | 2 | 362 |
| September | 58 | 153 |
| October | 298 | 27 |
| November | 654 | 1 |
| December | 995 | 0 |
| Year (annual) | 5,130 | 1,337 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00146128. 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 Ottawa been warmer than normal lately?
2025 averaged 55.1°F, 0.6°F above the 1991-2020 normal of 54.5°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 55.4°F | +0.9°F | 47.36 | – |
| 2022 | 53.9°F | −0.6°F | 35.70 | – |
| 2023 | 56.2°F | +1.7°F | 39.53 | – |
| 2025 | 55.1°F | +0.6°F | 34.99 | 9.5 |
Over 106 complete years from 1897 to 2025, the station's annual mean temperature rose at a fitted 0.5°F per century (+0.03°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00146128; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Ottawa's climate compare?
Ottawa is warmer than 54 of the other 136 places with their own NOAA record in Kansas, and wetter than 113. Across the 7,247 U.S. stations with normals, its annual mean of 54.5°F is warmer than 59%.
In the Köppen classification computed from these normals, Ottawa 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 Ottawa share this climate record?
3 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.
- Baldwin City, KS4,985 people · 12 mi NE
- Princeton, KS251 people · 9 mi S
- Centropolis, KS70 people · 8 mi NW
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 Ottawa's climate
What is the coldest month in Ottawa?
January, with a normal high of 40°F and a normal low of 18°F. The warmest is July (89°F by day, 68°F at night).
Does it snow in Ottawa?
Yes: 9 inches in a normal year, falling on 8 days with 0.1 inch or more, the most in January (3.2 inches).
What is the rainiest month in Ottawa?
May, with 5.82 in of precipitation in a normal year; the driest is January with 1.22 in.
What plant hardiness zone is Ottawa in?
The USDA's 2023 map puts Ottawa in zone 6b in ZIP code 66067, the nearest ZIP area. By the same method at Ottawa's NOAA station, the coldest night of a typical year reaches −5°F (27 years, 1991-2020): zone 6b.
How late can frost come in Ottawa?
In half of years the last 32°F night comes after April 18; in one year in ten it comes after May 1. Waiting until May 1 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Kansas climateThe statewide normals and every place in the state
- Pomona, KS16 miles from this station, 56.2°F a year
- Osawatomie, KS19 miles from this station, 55.0°F a year
- Hillsdale, KS21 miles from this station, 54.8°F a year
- Paola, KS22 miles from this station, 55.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made