Frost dates for Fargo, North Dakota
North Dakota · first & last freeze, from NOAA 1991–2020 climate normals
In a typical year, the last spring freeze around Fargo comes near May 4 and the first fall freeze near October 2. One year in ten, a freeze still arrives after May 18 in spring — and one year in ten, the first fall freeze has already landed by September 22. NCEI's own growing-season statistic (days between freezes, percentiled per year) puts the median at 151 days.
Freeze-date probabilities, three thresholds
| Threshold | Last spring — 9 in 10 years past by | Last spring — typical (median) | Last spring — 1 in 10 years later than | First fall — 1 in 10 years by | First fall — typical (median) | First fall — 9 in 10 years by |
|---|---|---|---|---|---|---|
| 36°F — near-freezing (frost can occur) | May 2 | May 13 | May 26 | September 12 | September 24 | October 5 |
| 32°F — freezing | April 21 | May 4 | May 18 | September 22 | October 2 | October 15 |
| 28°F — hard freeze | April 10 | April 25 | May 9 | September 29 | October 12 | October 26 |
Measured at Fargo 3S, ND (USC00322860), 2.9 mi from the city's census reference point, elev. 908 ft. NOAA/NCEI 1991–2020 normals. Read each date column as odds over the 30-year record — e.g. "9 in 10 years past by" means only one spring in ten saw a later freeze than that date.
Frost-free windows (computed)
| Window (32°F ends) | Opens | Closes | Length |
|---|---|---|---|
| Cautious (1-in-10 freeze risk at each end) | May 18 | September 22 | 127 days |
| Typical (median freeze dates) | May 4 | October 2 | 151 days |
| Gambler's (9-in-10 freeze risk at each end) | April 21 | October 15 | 177 days |
Pure arithmetic on the freeze-date percentiles above — the "cautious" window opens on the date only 1 year in 10 still sees a later spring freeze, and closes on the date by which only 1 year in 10 has already frozen.
About this city's numbers
- Census entity: Fargo city, North Dakota — official 2024 population estimate 136,285.
- Weather station: Fargo 3S, ND (USC00322860), 2.9 mi from the city's census-gazetteer reference point at elevation 908 ft. Frost dates are that station's history — neighborhoods vary.
- Data pulled 2026-09-05; normals period 1991-2020 (replaced by NOAA roughly once a decade).