Climate Ottawa - Illinois
| JanJa | FebFe | MarMa | AprAp | MayMa | JunJu | |
|---|---|---|---|---|---|---|
| Average high in ºF Av. high Hi | 31 | 36 | 49 | 62 | 72 | 81 |
| Average low in ºF Av. low Lo | 15 | 19 | 29 | 40 | 51 | 60 |
| Av. precipitation in inch Av. precip. Pre. | 1.48 | 1.43 | 2.46 | 3.22 | 4.11 | 3.98 |
| Av. snowfall in inch Snowfall Sn | 8 | 5 | 3 | 1 | 0 | 0 |
| JulJu | AugAu | SepSe | OctOc | NovNo | DecDe | |
|---|---|---|---|---|---|---|
| Average high in ºF Av. high Hi | 84 | 83 | 77 | 65 | 49 | 36 |
| Average low in ºF Av. low Lo | 64 | 62 | 54 | 42 | 30 | 20 |
| Av. precipitation in inch Av. precip. Pre. | 3.85 | 3.89 | 3.26 | 2.80 | 0.00 | 2.13 |
| Av. snowfall in inch Snowfall Sn | 0 | 0 | 0 | 0 | 0 | 5 |
What is the average weather in Ottawa, Illinois?
Ottawa experiences a humid continental climate, marked by very strong seasonal temperature contrasts. Summers are warm, while winters are cold and bring regular snowfall. The area is fairly wet, with precipitation spread relatively evenly throughout the year, though summers tend to be wetter and winters drier.
Ottawa Climate Graph - Illinois Climate Chart
Daily normals Ottawa - Illinois - January
Day | High ºF | Low ºF | Prec/mo inch | Prec/yr inch | Snow/mo inch | Snow/yr inch |
|---|---|---|---|---|---|---|
| 1 Jan | 31.9 | 17.1 | 0.06 | 0.06 | 0.30 | 0.30 |
| 2 Jan | 31.7 | 16.9 | 0.13 | 0.13 | 0.50 | 0.50 |
| 3 Jan | 31.5 | 16.7 | 0.19 | 0.19 | 0.80 | 0.80 |
| 4 Jan | 31.4 | 16.5 | 0.26 | 0.26 | 1.10 | 1.10 |
| 5 Jan | 31.2 | 16.3 | 0.32 | 0.32 | 1.40 | 1.40 |
| 6 Jan | 31.1 | 16.1 | 0.38 | 0.38 | 1.70 | 1.70 |
| 7 Jan | 31.0 | 15.9 | 0.45 | 0.45 | 2.00 | 2.00 |
| 8 Jan | 30.9 | 15.8 | 0.51 | 0.51 | 2.30 | 2.30 |
| 9 Jan | 30.8 | 15.6 | 0.58 | 0.58 | 2.70 | 2.70 |
| 10 Jan | 30.7 | 15.5 | 0.65 | 0.65 | 3.00 | 3.00 |
| 11 Jan | 30.6 | 15.3 | 0.72 | 0.72 | 3.30 | 3.30 |
| 12 Jan | 30.5 | 15.2 | 0.78 | 0.78 | 3.60 | 3.60 |
| 13 Jan | 30.4 | 15.0 | 0.85 | 0.85 | 3.90 | 3.90 |
| 14 Jan | 30.4 | 14.9 | 0.91 | 0.91 | 4.30 | 4.30 |
| 15 Jan | 30.3 | 14.8 | 0.97 | 0.97 | 4.60 | 4.60 |
| 16 Jan | 30.3 | 14.7 | 1.03 | 1.03 | 4.90 | 4.90 |
| 17 Jan | 30.2 | 14.6 | 1.09 | 1.09 | 5.30 | 5.30 |
| 18 Jan | 30.2 | 14.6 | 1.15 | 1.15 | 5.60 | 5.60 |
| 19 Jan | 30.2 | 14.5 | 1.21 | 1.21 | 5.90 | 5.90 |
| 20 Jan | 30.2 | 14.5 | 1.26 | 1.26 | 6.20 | 6.20 |
| 21 Jan | 30.2 | 14.4 | 1.31 | 1.31 | 6.50 | 6.50 |
| 22 Jan | 30.3 | 14.4 | 1.37 | 1.37 | 6.80 | 6.80 |
| 23 Jan | 30.3 | 14.4 | 1.42 | 1.42 | 7.10 | 7.10 |
| 24 Jan | 30.4 | 14.4 | 1.47 | 1.47 | 7.40 | 7.40 |
| 25 Jan | 30.4 | 14.5 | 1.52 | 1.52 | 7.70 | 7.70 |
| 26 Jan | 30.5 | 14.5 | 1.57 | 1.57 | 7.90 | 7.90 |
| 27 Jan | 30.6 | 14.6 | 1.61 | 1.61 | 8.20 | 8.20 |
| 28 Jan | 30.7 | 14.7 | 1.66 | 1.66 | 8.50 | 8.50 |
| 29 Jan | 30.8 | 14.8 | 1.70 | 1.70 | 8.70 | 8.70 |
| 30 Jan | 31.0 | 14.9 | 1.74 | 1.74 | 9.00 | 9.00 |
| 31 Jan | 31.1 | 15.0 | 1.78 | 1.78 | 9.20 | 9.20 |
Weather history Ottawa - September 2026
| Day | High ºF | Low ºF | Precip. inch | Snow inch | Snow d. inch |
|---|---|---|---|---|---|
| 01 Sep | 89.1 | 66.9 | 0.00 | - | - |
| 02 Sep | 91.9 | 72.0 | 0.00 | - | - |
| 03 Sep | 91.9 | 72.0 | 0.00 | - | - |
| 04 Sep | 90.0 | 73.9 | 0.00 | - | - |
| 05 Sep | 91.9 | 73.0 | 0.00 | - | - |
| 06 Sep | 87.1 | 64.9 | 0.00 | - | - |
| 07 Sep | 81.0 | 59.0 | 0.00 | - | - |
| 08 Sep | 81.0 | 59.0 | 0.00 | - | - |
| 09 Sep | 84.0 | 60.1 | 0.17 | - | - |
| 10 Sep | 77.0 | 64.9 | 0.08 | - | - |
| 11 Sep | 75.0 | 59.0 | 0.00 | - | - |
| 12 Sep | 80.1 | 59.0 | 0.00 | - | - |
| 13 Sep | 86.0 | 57.0 | 0.00 | - | - |
| 14 Sep | 70.0 | 50.0 | 0.00 | - | - |
| 15 Sep | - | - | - | - | - |
| 16 Sep | - | - | - | - | - |
| 17 Sep | 71.1 | 63.0 | 0.07 | - | - |
| 18 Sep | - | - | - | - | - |
| 19 Sep | 72.0 | 64.0 | 0.12 | - | - |
| 20 Sep | - | - | - | - | - |
| 21 Sep | - | - | - | - | - |
| 22 Sep | - | - | - | - | - |
| 23 Sep | - | - | - | - | - |
| 24 Sep | - | - | - | - | - |
| 25 Sep | - | - | - | - | - |
| 26 Sep | - | - | - | - | - |
| 27 Sep | - | - | - | - | - |
| 28 Sep | - | - | - | - | - |
| 29 Sep | - | - | - | - | - |
| 30 Sep | - | - | - | - | - |
Past weather Ottawa
| Sep 26 | Normal | ||
|---|---|---|---|
| Average high temperature Av. high temp. | 82.4 ºF | 31 ºF | |
| Average low temperature Av. low temp. | 63.6 ºF | 15 ºF | |
| Total precipitation Total precip. | 0.44 inch | 1.48 inch | |
| Total snowfall Total snowfall | - inch | 8 inch | |
| Highest max temperature Highest max temp. | 91.9 ºF | - | |
| Lowest max temperature Lowest max temp. | 70.0 ºF | - | |
| Highest min temperature Highest min temp. | 73.9 ºF | - | |
| Lowest min temperature Lowest min temp. | 50.0 ºF | - | |
Past weather September 2026 incomplete - Missing data
Geo Ottawa - Illinois
| Country | United States | |
|---|---|---|
| State | Illinois | |
| County | LaSalle | |
| City | Ottawa | |
| Zip Code | 61350 | |
| Longitude | -88.79 dec. degr. | |
| Latitude | 41.4 dec. degr. | |
| Altitude - Elevation | 617ft | |
| ICAO | - | |
| IATA | - |
Date and Time Ottawa - Illinois
| Local Time | 07:31 AM | |
|---|---|---|
| Sunrise | 06:40 AM | |
| Sunset | 06:55 PM | |
| Day/Night | Day | |
| Timezone | Central Daylight Time | |
| Timezone DB | America - Chicago |
Map of Ottawa - Illinois
USGS National Map — Open interactive map
Ottawa weather averages
| Annual high temperature | 60ºF |
| Annual low temperature | 41ºF |
| Average annual precip. | 32.61 inch |
| Av. annual snowfall | 22 inch |
Station Data
Monthly averages Ottawa
Longitude: -88.7939, Latitude: 41.3998
Average weather Ottawa, IL - 61350
Monthly: 1991-2020 normals
History: 2007-2026
Abbreviations
Average precipitation in : Av. precipitation in
Jan: January, Feb: February, ...Jan: January, Feb: February, ...Ja: January, Fe: February, ...