Best time to visit Iowa City
The best time to visit Iowa City is September, judged on twenty years of weather records and the events worth going for.
Iowa City, Iowa, United States
°C
mm
- Average daily high and low
- Precipitation
- Good month
- Best month
- Made good or best by an event
| Month | Average daily high | Average daily low | Precipitation | Verdict |
|---|---|---|---|---|
| January | -1.5 °C / 29 °F | -9.8 °C / 14 °F | 41 mm / 1.6 in | neither best nor good |
| February | 0.3 °C / 33 °F | -9 °C / 16 °F | 45 mm / 1.8 in | neither best nor good |
| March | 9.2 °C / 49 °F | -0.7 °C / 31 °F | 77 mm / 3 in | neither best nor good |
| April | 15.8 °C / 60 °F | 4.9 °C / 41 °F | 115 mm / 4.5 in | good month |
| May | 22.2 °C / 72 °F | 11.7 °C / 53 °F | 116 mm / 4.6 in | good month |
| June | 27.4 °C / 81 °F | 17.4 °C / 63 °F | 134 mm / 5.3 in | good month |
| July | 28.6 °C / 83 °F | 19.1 °C / 66 °F | 89 mm / 3.5 in | good month |
| August | 27.6 °C / 82 °F | 17.6 °C / 64 °F | 93 mm / 3.7 in | good month |
| September | 24.8 °C / 77 °F | 13.4 °C / 56 °F | 88 mm / 3.4 in | best month |
| October | 17.4 °C / 63 °F | 6.7 °C / 44 °F | 84 mm / 3.3 in | good month |
| November | 9.4 °C / 49 °F | -0.2 °C / 32 °F | 56 mm / 2.2 in | neither best nor good |
| December | 1.9 °C / 35 °F | -6.1 °C / 21 °F | 57 mm / 2.2 in | neither best nor good |
Good and best months depend on more than temperature, rain and events. How they are chosen
Each activity on this page has its own good and best months, rated on twenty years of daily weather records. Which measures count, and how much, depends on the activity: humidity for exploring outdoors, wind for the beach, hiking and skiing, snow for skiing alone. Between them, the activities are rated on:
- Daytime highs
- Night-time lows
- How warm it feels
- Humidity
- How much of the day is sunny
- Hours of daylight
- Monthly rainfall
- How many days it rains
- Days of heavy rain
- Wind
- Snowfall and days with snow
- Major events, such as festivals
The chart shows the good and best months for exploring outdoors.
The event icon marks a month that an event lifts to good or best, such as a festival or a natural spectacle. Choose “Weather only” in the toolbar to rate the months on weather alone.
Best months by activity
Exploring outdoors
Mild days and nights, mostly dry and bright. The default for 'when should I go'.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: good
- MMay: good
- JJune: good
- JJuly: good
- AAugust: good
- SSeptember: best
- OOctober: good
- NNovember: neither
- DDecember: neither
- Best
- September
- Good
- April–August, October
Why these months
April · good
In its favour: share of daylight that is sunny 68%, average daily high 15.8 °C / 60 °F, feels like (high) 12.6 °C / 55 °F, precipitation 115 mm / 4.5 in, relative humidity 63%, wet days 11.2 days, days with heavy rain 4.1 days, average daily low 4.9 °C / 41 °F.
May · good
In its favour: feels like (high) 21.1 °C / 70 °F, average daily high 22.2 °C / 72 °F, share of daylight that is sunny 71%, precipitation 116 mm / 4.6 in, average daily low 11.7 °C / 53 °F, relative humidity 66%, days with heavy rain 4.5 days.
Against: wet days 12.7 days.
June · good
In its favour: feels like (high) 28.7 °C / 84 °F, share of daylight that is sunny 77%, average daily high 27.4 °C / 81 °F, average daily low 17.4 °C / 63 °F, wet days 11 days, relative humidity 69%, days with heavy rain 4.4 days.
Against: precipitation 134 mm / 5.3 in.
July · good
In its favour: share of daylight that is sunny 83%, precipitation 89 mm / 3.5 in, average daily high 28.6 °C / 83 °F, wet days 9.7 days, days with heavy rain 3.2 days, average daily low 19.1 °C / 66 °F, relative humidity 73%.
Against: feels like (high) 31.3 °C / 88 °F.
August · good
In its favour: share of daylight that is sunny 83%, feels like (high) 29.7 °C / 85 °F, average daily high 27.6 °C / 82 °F, precipitation 93 mm / 3.7 in, wet days 8.6 days, days with heavy rain 2.8 days, average daily low 17.6 °C / 64 °F, relative humidity 74%.
September · best
In its favour: feels like (high) 24.4 °C / 76 °F, average daily high 24.8 °C / 77 °F, share of daylight that is sunny 80%, precipitation 88 mm / 3.4 in, wet days 7.8 days, days with heavy rain 2.7 days, average daily low 13.4 °C / 56 °F, relative humidity 70%.
October · good
In its favour: feels like (high) 14.4 °C / 58 °F, share of daylight that is sunny 69%, average daily high 17.4 °C / 63 °F, precipitation 84 mm / 3.3 in, wet days 9.1 days, days with heavy rain 2.9 days, relative humidity 67%, average daily low 6.7 °C / 44 °F.
An activity is listed only where it applies: skiing at ski destinations, beach and swimming at beach destinations. The nearest ski area is Sugar Mountain Resort, 1037 km away.
Weather averages
Monthly averages over twenty years, 2006–2025. Highs, lows and precipitation are in the chart at the top.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels like (high) | -6.5 °C | -4.7 °C | 4.9 °C | 12.6 °C | 21.1 °C | 28.7 °C | 31.3 °C | 29.7 °C | 24.4 °C | 14.4 °C | 5.2 °C | -2.6 °C |
| Days with heavy rain | 1 days | 1.4 days | 2.8 days | 4.1 days | 4.5 days | 4.4 days | 3.2 days | 2.8 days | 2.7 days | 2.9 days | 1.6 days | 1.9 days |
| Time rain usually falls | 6 pm | 5 pm | 10 pm | 8 pm | 4 am | 1 am | 7 pm | 3 am | 2 am | 8 pm | 10 pm | 11 pm |
| Sunshine per day | 6 h | 7.7 h | 8.3 h | 9.1 h | 10.4 h | 11.7 h | 12.3 h | 11.5 h | 10 h | 7.7 h | 6.9 h | 5.4 h |
| Relative humidity | 76% | 72% | 68% | 63% | 66% | 69% | 73% | 74% | 70% | 67% | 70% | 77% |
Air quality
Averaged over a shorter period (2022–2025) than the twenty-year averages above, and not counted towards good or best months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollution (PM2.5) 2022–2025 | 8.2 µg/m³ | 9.7 µg/m³ | 8.1 µg/m³ | 8.2 µg/m³ | 9.4 µg/m³ | 14.5 µg/m³ | 12.6 µg/m³ | 9.8 µg/m³ | 7.9 µg/m³ | 5.6 µg/m³ | 5.9 µg/m³ | 6.9 µg/m³ |
| Air pollution (PM2.5, daily peak) 2022–2025 | 13.1 µg/m³ | 14.5 µg/m³ | 13.3 µg/m³ | 14.4 µg/m³ | 15.1 µg/m³ | 21.8 µg/m³ | 18.3 µg/m³ | 14.2 µg/m³ | 12.2 µg/m³ | 8.8 µg/m³ | 9.4 µg/m³ | 11.1 µg/m³ |
- Good 15 µg/m³ or less
- Fair 15 to 25 µg/m³
- Moderate 25 to 37.5 µg/m³
- Poor 37.5 to 50 µg/m³
- Very poor 50 to 75 µg/m³
- Extremely poor over 75 µg/m³
Each figure is compared with the World Health Organization's guideline for a day's air, 15 µg/m³ or less, and with its interim targets above that. The words are ours: the WHO does not name its steps. The figures are modelled monthly averages, so single days can be well above them. The daily peak is the average of each day's highest hour, shaded on the same scale.