Crystal Lake, IA Weather & Growing Conditions
Overnight
61°F
Patchy Fog
Patchy fog and a chance of showers and thunderstorms. Cloudy. Low around 61, with temperatures rising to around 65 overnight. East wind around 6 mph. Chance of precipitation is 50%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 61°F | Patchy Fog | 6 mph E | 45% |
| Saturday | 70°F | Patchy Fog | 6 to 9 mph NNE | 48% |
| Saturday Night | 55°F | Slight Chance Rain Showers then Cloudy | 9 to 13 mph NNE | 23% |
| Sunday | 66°F | Mostly Cloudy | 15 mph NE | 9% |
| Sunday Night | 51°F | Chance Rain Showers | 9 to 13 mph ENE | 29% |
| Monday | 61°F | Chance Rain Showers | 12 mph ENE | 34% |
| Monday Night | 46°F | Chance Rain Showers then Mostly Cloudy | 5 to 9 mph ENE | 30% |
| Tuesday | 61°F | Mostly Sunny | 5 to 8 mph E | 7% |
| Tuesday Night | 42°F | Mostly Clear | 2 to 6 mph ESE | 1% |
| Wednesday | 64°F | Sunny | 6 mph ESE | 1% |
| Wednesday Night | 47°F | Partly Cloudy then Slight Chance Rain Showers | 3 mph SE | 15% |
| Thursday | 66°F | Slight Chance Rain Showers then Partly Sunny | 2 to 6 mph SE | 15% |
| Thursday Night | 51°F | Mostly Cloudy | 3 mph SE | 4% |
| Friday | 68°F | Partly Sunny | 2 to 7 mph SE | 6% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Crystal Lake, IA
Last spring frost
Apr 29
First fall frost
Oct 7
Growing season
161 days
Hardiness zone
5a
Explore more for Crystal Lake, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Britt 3E, Ia (8.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.