The year at a glance
Averages from 30 years of climate history, 1991-2020
| Grimes | Metric | Johnston |
|---|---|---|
| 203 days | Sunny daysclear or partly cloudy skies | 203 days |
| 38 in | Precipitationper year | 38 in |
| 114 days | Wet daysrain or snow per year | 114 days |
| 34 in | Snowfallper year | 34 in |
| 19 days | Hot daysabove 90 °F | 19 days |
| 134 days | Freezing nightsat or below 32 °F | 134 days |
| 70% | Humidityaverage relative | 70% |
| 50 °F | Average temperatureyear round | 50 °F |
Monthly temperatures
Average daily high and low for each month, in °F. The gap between the two lines is what an ordinary day feels like across the year.
Daily highs
Daily lows
View monthly temperatures as a table
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grimes high | 30 | 35 | 48 | 61 | 72 | 81 | 85 | 83 | 76 | 63 | 48 | 35 |
| Johnston high | 30 | 35 | 48 | 61 | 72 | 81 | 85 | 83 | 76 | 63 | 48 | 35 |
| Grimes low | 13 | 17 | 29 | 40 | 51 | 62 | 65 | 63 | 55 | 42 | 30 | 19 |
| Johnston low | 13 | 17 | 28 | 40 | 51 | 62 | 65 | 63 | 55 | 42 | 30 | 19 |
Monthly precipitation
Total rain plus melted snow for each month, in inches. Taller bars mean wetter months.
View monthly precipitation as a table
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grimes | 1.2 | 1.5 | 2.6 | 4.3 | 5.5 | 5.0 | 3.7 | 3.9 | 3.5 | 2.9 | 2.1 | 1.6 |
| Johnston | 1.2 | 1.5 | 2.6 | 4.3 | 5.5 | 5.0 | 3.7 | 3.9 | 3.5 | 2.9 | 2.1 | 1.6 |
Monthly sunny days
Days each month with clear or partly cloudy skies, so compare the same month between cities.
View monthly sunny days as a table
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grimes | 14 | 13 | 16 | 14 | 16 | 17 | 21 | 21 | 21 | 19 | 16 | 15 |
| Johnston | 14 | 13 | 16 | 14 | 16 | 17 | 21 | 21 | 21 | 19 | 16 | 15 |
Keep comparing
Nearby cities and popular picks for each side of this matchup. Any two cities can be compared from the home page.
Grimes vs another city
- Grimes vs Urbandale, IA
- Grimes vs Clive, IA
- Grimes vs Windsor Heights, IA
- Grimes vs Waukee, IA
- Grimes vs Polk City, IA
- Grimes vs New York, NY
- Grimes vs Los Angeles, CA
- Grimes vs Chicago, IL
- Grimes vs Houston, TX
- Grimes vs Phoenix, AZ
- Grimes vs Philadelphia, PA
Johnston vs another city
- Johnston vs Urbandale, IA
- Johnston vs Windsor Heights, IA
- Johnston vs Polk City, IA
- Johnston vs Clive, IA
- Johnston vs Ankeny, IA
- Johnston vs New York, NY
- Johnston vs Los Angeles, CA
- Johnston vs Chicago, IL
- Johnston vs Houston, TX
- Johnston vs Phoenix, AZ
- Johnston vs Philadelphia, PA
About this data
Every figure on this page is a 30 year average computed from daily climate history for 1991-2020, using each city's own coordinates. Wet days count days with measurable precipitation, calibrated against the wet day counts in NOAA's published climate normals. Sunny days count clear plus partly cloudy days, defined as average cloud cover of 63 percent or less and calibrated against NOAA's published sky cover tables. Snowfall figures are model estimates anchored to NOAA station measurements near each city.
Weather data by Open-Meteo.com (CC BY 4.0). Contains modified Copernicus Climate Change Service information (ERA5, ERA5-Land).