Climate averages 1991–2020
Olathe weather
in September.
A warm, wet month: the 4th warmest and the joint 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Olathe: daytime highs average 25.4°C and nights cool to about 16.4°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 93 mm of rain on roughly 8 days, which makes September a wet month (the joint 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 29 min on an average September day.
The nearest other city in this atlas is Overland Park (17 km away). In September its highs average 25.3°C, about as warm as Olathe, with 93 mm of rain.
Among the 498 cities listed in the United States, Olathe ranks joint 297th of 498 for the warmest September highs and joint 358th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Olathe is 1.4°C cooler than that mean.
From September to October, average highs fall by 6.8°C to 18.7°C, and monthly rainfall falls from 93 mm to 83 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Olathe climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 3.5°C-5.3°C | -5.3°C | 35 | 5.6 | 9.810 h |
| February | 6.3°C-3.2°C | -3.2°C | 47 | 6.0 | 10.711 h |
| March | 12.3°C2.1°C | 2.1°C | 76 | 9.1 | 11.912 h |
| April | 17.9°C7.8°C | 7.8°C | 120 | 11.1 | 13.213 h |
| May | 23.2°C13.8°C | 13.8°C | 144 | 12.7 | 14.314 h |
| June | 28.4°C19.2°C | 19.2°C | 122 | 11.3 | 14.815 h |
| July | 30.7°C21.8°C | 21.8°C | 91 | 9.4 | 14.615 h |
| August | 30.0°C21.0°C | 21.0°C | 93 | 9.0 | 13.714 h |
| September, selected | 25.4°C16.4°C | 16.4°C | 93 | 8.1 | 12.512 h |
| October | 18.7°C9.8°C | 9.8°C | 83 | 8.0 | 11.211 h |
| November | 11.3°C3.1°C | 3.1°C | 58 | 6.4 | 10.110 h |
| December | 5.4°C-2.7°C | -2.7°C | 45 | 5.6 | 9.59 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Overland Park in SeptemberUnited States · 17 kmHigh 25.3°C · Low 16.3°C · 93 mm rain
- Kansas City in SeptemberUnited States · 32 kmHigh 25.6°C · Low 16.2°C · 93 mm rain
- Lawrence (Kansas), United States in SeptemberUnited States · 37 kmHigh 25.8°C · Low 16.5°C · 90 mm rain
- Lee's Summit in SeptemberUnited States · 38 kmHigh 25.3°C · Low 16.2°C · 93 mm rain
- Independence in SeptemberUnited States · 42 kmHigh 25.2°C · Low 16.1°C · 93 mm rain
- Topeka in SeptemberUnited States · 77 kmHigh 25.9°C · Low 16.3°C · 87 mm rain
- Saint Joseph in SeptemberUnited States · 99 kmHigh 25.2°C · Low 15.7°C · 85 mm rain
- Columbia (Missouri), United States in SeptemberUnited States · 215 kmHigh 26.1°C · Low 16.5°C · 86 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Olathe) is explained once on the Olathe year overview and on the Sources, method and limits page.
Overland Park lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.