Frost dates for Connell 1 W, WA
At Connell 1 W, the median last spring frost (32°F) is Apr 30 and the median first fall frost is Oct 12, for a typical growing season of 165 days. For a 90% chance that the last frost has passed, wait until May 15. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 30Last spring frost (median)50% chance of 32°F after this date
- May 15Safer planting date10% chance of 32°F after this date
- Oct 12First fall frost (median)50% chance of 32°F by this date
- 165 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 | Apr 30 | May 13 | May 31 |
| 32°F | Apr 12 | Apr 30 | May 15 |
| 28°F | Mar 20 | Apr 10 | May 1 |
| 24°F | Feb 23 | Mar 17 | Apr 7 |
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 | Sep 15 | Oct 1 | Oct 14 |
| 32°F | Sep 29 | Oct 12 | Oct 26 |
| 28°F | Oct 8 | Oct 24 | Nov 10 |
| 24°F | Oct 20 | Nov 4 | Nov 28 |
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 | 117 days | 139 days | 159 days |
| 32°F | 144 days | 165 days | 187 days |
| 28°F | 173 days | 197 days | 222 days |
| 24°F | 206 days | 232 days | 265 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 |
|---|---|---|---|
| 99326 | 7a | 0 to 5°F | 3 km |
| 99344 | 7a | 0 to 5°F | 28 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 USC00451690, at 46.6644, -118.8828, elevation 311 m (1,020 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 115.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Hatton 9 SE (19 km)
- Sagemoor (33 km)
- Eltopia 8 WSW (36 km)
- Lind 3 NE (45 km)
- Ice Harbor Dam (47 km)
- Pasco Tri Cities Airport (48 km)
- Richland (49 km)
- Kennewick (53 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.