Frost dates for Moro, OR
At Moro, the median last spring frost (32°F) is May 12 and the median first fall frost is Oct 4, for a typical growing season of 143 days. For a 90% chance that the last frost has passed, wait until May 31. Nearby ZIP codes are in USDA hardiness zones 7a to 7b.
- May 12Last spring frost (median)50% chance of 32°F after this date
- May 31Safer planting date10% chance of 32°F after this date
- Oct 4First fall frost (median)50% chance of 32°F by this date
- 143 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | May 16 | Jun 5 | Jun 30 |
| 32°F | Apr 27 | May 12 | May 31 |
| 28°F | Apr 8 | Apr 26 | May 11 |
| 24°F | Mar 9 | Apr 3 | Apr 25 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Aug 30 | Sep 19 | Oct 4 |
| 32°F | Sep 16 | Oct 4 | Oct 18 |
| 28°F | Oct 1 | Oct 16 | Nov 2 |
| 24°F | Oct 14 | Oct 31 | Nov 21 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 72 days | 102 days | 128 days |
| 32°F | 115 days | 143 days | 164 days |
| 28°F | 150 days | 173 days | 196 days |
| 24°F | 180 days | 210 days | 240 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 97039 | 7a | 0 to 5°F | 8 km |
| 97065 | 7b | 5 to 10°F | 15 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00355734, at 45.4825, -120.7236, elevation 570 m (1,870 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 126.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Kent (32 km)
- Dufur (32 km)
- The Dalles (40 km)
- Arlington (48 km)
- Condon (50 km)
- Hood River Exp. Station (66 km)
- Fossil (67 km)
- Parkdale 1 NNE (68 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.