Frost date probability · Oregon
Deschutes County frost dates. Probability table.
The median last spring frost in Deschutes County is —. The median first fall frost is —, giving a typical growing season of 0 days.
- USDA Zone 8b
- 9.4 mi to NOAA station
- 30-yr record (1991–2020)
Data from SUNRIVER, OR US, 9.4 miles away with 25-year NOAA record (1991-2020).
Annual overview
The frost year, at a glance.
Annual frost timeline · Deschutes County
Probability tables
Pick your row by your appetite for risk.
Five risk tiers across three temperature thresholds. Most farmers plan against the conservative side for high-value transplants and the median for direct-seed crops. The aggressive rows are useful when paired with row cover or other season-extension tools.
Last Spring Frost
The range of last-frost dates seen across 1991–2020 at the killing-freeze (28°F) threshold and at the lighter 32°F and harder 24°F thresholds. For frost-sensitive transplants in Deschutes County, the "very conservative" row is the date frost has occurred at in only 1 of 10 historical years — i.e., the safe-side bound.
Reading: pick a row by your appetite for risk. Very conservative — the unluckiest 10% of years had frost past this date. Very aggressive — only the luckiest 10% of years were frost-free this early. Plant frost-sensitive transplants on the conservative side.
First Fall Frost
The range of first-frost dates in fall. For frost-sensitive harvests (winter squash, fall tomatoes, pumpkins), the "very conservative" row is the harvest deadline — frost has arrived this early in only 1 of 10 historical years.
Reading: pick a row by your appetite for risk. Very conservative — frost arrived this early in only the unluckiest 10% of years. Very aggressive — frost held off this late in only the luckiest 10% of years. Schedule frost-sensitive harvests on the conservative side.
Growing Season
Days between the last spring frost (28°F) and first fall frost (28°F). Plan for the shorter end if you're growing long-season crops without season-extension tools.
Short year (10%)
Plan for this if you can't afford a frost-shortened season.
Median year (50%)
Half of historical years gave you at least this much.
Long year (90%)
The upside — a ninth of years run this long or longer.
What this means for your crops
Crop-specific planting and harvest guidance derived from the frost probability data above. Each line uses the actual percentile dates from the nearest NOAA station — not a generic regional rule.
Tomatoes
Full Oregon calendar →Transplant after the last killing freeze when soil reaches 60°F.Peppers
Full Oregon calendar →Transplant after soil reaches 65°F.Sweet corn
Full Oregon calendar →Direct seed when soil reaches 55°F.Pumpkins
Full Oregon calendar →Plant by mid-summer for fall harvest.Potatoes
Full Oregon calendar →Plant when soil reaches 45°F.Winter wheat
Full Oregon calendar →Plant 6 weeks before first hard freeze.Clover (cool-season)
Full Oregon calendar →Frost-seed in late winter or plant 6 weeks before fall frost.Winter rye (cover)
Full Oregon calendar →Plant 4 weeks before first hard freeze.
These dates assume a healthy, well-drained field and standard varieties. Adjust for raised beds, row cover, or short-season varieties as appropriate.
Local variation
Why your farm may differ from these dates.
The dates on this page come from the nearest qualifying NOAA station with a 30-year record. Real frost on a real field is shaped by terrain, water, and the built environment. Read the station data as a regional anchor, then adjust for what you know about your own ground.
Elevation
Higher ground frosts earlier in fall and later in spring. As a rule of thumb, expect roughly a 3–5°F difference in overnight low for every 1,000 feet of elevation change versus the nearest valley station.
Cold air drainage
On clear, calm nights cold air sinks into low spots. Valley bottoms, hollows, and the bottom of orchard rows can frost 2–6 weeks differently than nearby slopes — even within a 100-yard radius. South-facing slopes warm faster in spring than north-facing slopes.
Urban and suburban heat
Pavement, buildings, and irrigation push frost dates later than rural stations report. If your operation sits inside a metro area, the local last-frost date is often 1–3 weeks earlier than what a rural NOAA station shows.
Water proximity
Large lakes, rivers, and especially the coast moderate temperature swings. Sites within a mile of a sizable water body typically see a later last-spring frost and an earlier first-fall frost than inland sites at the same latitude.
For precision frost monitoring, install a personal weather station on the field that matters most. The closer the sensor is to the soil surface where you actually plant, the more useful the data.
Hardiness zone comparison
How this compares to USDA Zone 8b.
USDA Zone 8b measures average annual extreme minimum winter temperature for plant winter hardiness. The frost probability data on this page measures the actual range of last-spring and first-fall frost dates from the nearest NOAA weather station — far more useful for planning annual crop planting and harvest.
USDA Hardiness Zone
Measures the average annual minimum winter temperature. Designed to predict whether a perennial plant survives winter in your location — useful for orchard, vine, and ornamental decisions, but says nothing about when last spring frost arrives or how variable that date is.
Frost probability data
Measures the actual statistical distribution of last-spring and first-fall frost dates from a 30-year NOAA record. Designed for annual-crop planning — when to plant transplants, when to direct-seed, when to expect a hard harvest deadline.
Source data
The NOAA station behind these dates.
SUNRIVER, OR US
Distance
9.4 miles from county centroid
Elevation
4180 ft
Record period
1991–2020
Network
NOAA Climate Normals
Cross-validation stations
- BEND, OR US10.2 mi30-yr record
- BEND 7 NE, OR US14.1 mi30-yr record
- REDMOND ROBERTS FLD, OR US23.9 mi30-yr record
Nearby counties
Frost dates in nearby Oregon counties.
Jefferson County
Spring May 2 · Fall Oct 17
Crook County
Spring May 12 · Fall Sep 30
Wasco County
Spring Apr 24 · Fall Oct 24
Klamath County
Spring Jun 10 · Fall Sep 13
Lake County
Spring May 10 · Fall Sep 28
Linn County
Spring Mar 30 · Fall Nov 5
Wheeler County
Spring Apr 30 · Fall Oct 22
Clackamas County
Spring Feb 26 · Fall Nov 30
Historical averages are the floor. Tonight's risk is the truth.
Bield Farm pulls live forecast data for your specific farm location and tells you when frost is actually coming — paired with the historical baseline above so you know whether tonight's risk is normal or anomalous.
Start free trial →