Diagonal, IA Weather & Growing Conditions
Today
86°F
Partly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 3pm. Partly sunny. High near 86, with temperatures falling to around 84 in the afternoon. Southeast wind 3 to 8 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Partly Sunny then Chance Showers And Thunderstorms | 3 to 8 mph SE | 29% |
| Tonight | 64°F | Showers And Thunderstorms Likely | 10 mph NNE | 67% |
| Wednesday | 74°F | Showers And Thunderstorms Likely | 9 mph NE | 80% |
| Wednesday Night | 59°F | Chance Showers And Thunderstorms | 3 to 10 mph NE | 43% |
| Thursday | 81°F | Mostly Sunny | 5 mph E | 9% |
| Thursday Night | 62°F | Mostly Clear | 3 mph ESE | 8% |
| Friday | 86°F | Mostly Sunny | 3 to 7 mph S | 8% |
| Friday Night | 67°F | Mostly Clear | 6 mph S | 8% |
| Saturday | 90°F | Sunny | 5 to 10 mph S | 3% |
| Saturday Night | 72°F | Mostly Clear | 13 mph S | 8% |
| Sunday | 92°F | Mostly Sunny | 10 to 14 mph SSW | 7% |
| Sunday Night | 72°F | Partly Cloudy | 14 mph S | 12% |
| Monday | 92°F | Mostly Sunny | 12 to 16 mph SSW | 12% |
| Monday Night | 72°F | Slight Chance Showers And Thunderstorms | 15 mph S | 21% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Diagonal, IA
Last spring frost
Apr 25
First fall frost
Oct 12
Growing season
169 days
Hardiness zone
5b
Explore more for Diagonal, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Mt Ayr, Ia (9.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.