Diagonal, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Diagonal, a city in Ringgold County, Iowa.
Tonight
69°F
Mostly Cloudy then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 69. South wind around 9 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Diagonal
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 69°F | Mostly Cloudy then Chance Showers And Thunderstorms | 9 mph S | 34% |
| Saturday | 83°F | Chance Showers And Thunderstorms | 9 mph SW | 38% |
| Saturday Night | 63°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 8 mph N | 59% |
| Sunday | 69°F | Chance Showers And Thunderstorms | 8 to 12 mph NNE | 54% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms | 10 mph NE | 54% |
| Monday | 61°F | Showers And Thunderstorms Likely | 10 mph NE | 56% |
| Monday Night | 52°F | Chance Showers And Thunderstorms | 9 mph NE | 52% |
| Tuesday | 60°F | Mostly Cloudy | 9 mph NE | 9% |
| Tuesday Night | 47°F | Mostly Cloudy | 3 to 7 mph NE | 4% |
| Wednesday | 63°F | Mostly Sunny | 5 mph ENE | 2% |
| Wednesday Night | 51°F | Partly Cloudy | 2 mph E | 5% |
| Thursday | 65°F | Slight Chance Rain Showers | 3 mph ESE | 19% |
| Thursday Night | 55°F | Slight Chance Rain Showers | 2 mph ESE | 17% |
| Friday | 66°F | Slight Chance Rain Showers | 2 to 6 mph ESE | 17% |
Forecast source: National Weather Service (api.weather.gov) for Diagonal (40.811, -94.342). Updated through the day.
Growing snapshot for Diagonal
Last spring frost
Apr 25
First fall frost
Oct 12
Growing season
169 days
Hardiness zone
5b
More local growing data for Diagonal: nearby ZIP 50845 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Mt Ayr, Ia (9.5 mi from Diagonal). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.