Armstrong, IA Weather & Growing Conditions
Overnight
60°F
Patchy Fog
Patchy fog and a chance of showers and thunderstorms. Cloudy. Low around 60, with temperatures rising to around 62 overnight. East northeast wind around 6 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 60°F | Patchy Fog | 6 mph ENE | 38% |
| Saturday | 68°F | Patchy Fog | 6 to 13 mph N | 36% |
| Saturday Night | 56°F | Slight Chance Rain Showers then Cloudy | 13 mph NNE | 23% |
| Sunday | 66°F | Mostly Cloudy | 16 mph NE | 14% |
| Sunday Night | 51°F | Chance Rain Showers | 9 to 13 mph ENE | 36% |
| Monday | 61°F | Chance Rain Showers | 10 mph ENE | 36% |
| Monday Night | 46°F | Chance Rain Showers then Mostly Cloudy | 5 to 9 mph ENE | 29% |
| Tuesday | 63°F | Mostly Sunny | 5 to 8 mph E | 5% |
| Tuesday Night | 43°F | Mostly Clear | 3 to 7 mph ESE | 1% |
| Wednesday | 65°F | Sunny | 3 to 7 mph SE | 2% |
| Wednesday Night | 48°F | Partly Cloudy | 5 mph SE | 11% |
| Thursday | 67°F | Slight Chance Rain Showers | 3 to 7 mph SSE | 17% |
| Thursday Night | 52°F | Partly Cloudy | 5 mph SE | 7% |
| Friday | 70°F | Mostly Sunny | 3 to 8 mph SE | 7% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Armstrong, IA
Last spring frost
May 4
First fall frost
Oct 1
Growing season
150 days
Hardiness zone
5a
Explore more for Armstrong, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Swea City 5N, Ia (8.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.