U.S. Frost Dates by Weather Station

NOAA station USW00024257 · California

Frost Dates for Redding, CA

NOAA weather station Redding Municipal Airport (USW00024257), California · elevation 497 ft (152 m) · hardiness zone 9a*

  • Lower-risk planting dateafter April 9only 1 spring in 10 still has a frost later
  • Typical last frostMarch 350% chance of a frost after it
  • Typical first fall frostNovember 2150% chance of a frost before it
  • Frost-free season261 daystypical year, 32°F
  • Hardiness zone9acalculated*

The year at a glance

Frost season at Redding, CASpring: a frost after January 31 in 9 years out of 10, after March 3 in half of the years, after April 9 in 1 year out of 10. Fall: the first frost comes before November 7 in 1 year out of 10, before November 21 in half of the years, before December 7 in 9 years out of 10. Typical frost-free season: 261 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 3First frost ~Nov 21Frost season at Redding, CASpring: a frost after January 31 in 9 years out of 10, after March 3 in half of the years, after April 9 in 1 year out of 10. Fall: the first frost comes before November 7 in 1 year out of 10, before November 21 in half of the years, before December 7 in 9 years out of 10. Typical frost-free season: 261 days.JFMAMJJASONDLast frost ~Mar 3First frost ~Nov 21
frost likely chance fading 90% → 10% frost-free in a typical yearThe year at a glance. Blue: frost is likely; the gradient fades as the chance drops from 90% to 10%; green: the frost-free part of a typical year.

Frost dates (32°F)

Probability of frost, based on 25 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 9November 7
50% (typical)March 3November 21
90% (likely)January 31December 7
Frost-free season (32°F, 50% chance)
261 days
Hard frost (28°F), last in spring, 50% chance after
January 27
Hard frost (28°F), first in fall, 50% chance before
December 7

The last 15 years (2006–2020 normals)

Typical last frost March 6 (3 days later than the 30-year normal), typical first fall frost November 22 (1 day later). Frost-free season 257 days.

A shorter, more recent NOAA period. The 30-year normals above remain the main reference: 15 years carry more year-to-year noise.

Add these dates to your calendar Yearly reminders for the typical last frost, the lower-risk planting date and the typical first fall frost (.ics).

How the chance of frost changes with the date

Spring at Redding: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 9, 20% March 31, 30% March 17, 40% March 9, 50% March 3, 60% February 27, 70% February 21, 80% February 13, 90% January 31. Observed last spring frost in recent years: 2021 February 27, 2022 April 12, 2023 April 4, 2024 February 8, 2025 March 18, 2026 February 20.Spring: last frostChance of a frost after this date10%50%90%Feb 1Mar 1Apr 1Apr 9Mar 3Jan 312021: February 272022: April 122023: April 42024: February 82025: March 182026: February 20Fall at Redding: chance of a frost before this dateFall, chance of a frost before the date: 10% November 7, 20% November 11, 30% November 16, 40% November 19, 50% November 21, 60% November 24, 70% November 28, 80% December 1, 90% December 7. Observed first fall frost in recent years: 2021 December 10, 2022 November 20, 2023 November 26, 2024 November 28, 2025 December 1.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Nov 7Nov 21Dec 72021: December 102022: November 202023: November 262024: November 282025: December 1
Two charts, because spring and fall answer different questions: in spring, the chance that a frost still comes after a date; in fall, the chance that the first frost has already come before it. NOAA publishes these odds from 10% to 90%, so the lines stop there. ◆ marks the actual date in each recent year.

What actually happened in recent years

Observed dates of the last spring and first fall frost (32°F) at this station; ◆ marks them on the charts above
YearLast spring frostFirst fall frost
2021February 27December 10
2022April 12November 20
2023April 4November 26
2024February 8November 28
2025March 18December 1
2026February 20season not over yet

What these dates mean

November 7 is the cautious fall date in Redding for finishing the harvest, with only a 10 % chance that a light frost has arrived earlier. The 50 % date, November 21, marks a point where there is a 50 % chance of a light frost earlier than this date, and December 7 carries a 90 % chance that a light frost will already be present, making a late-season tender crop a gamble.

In spring the cautious date for setting out tender crops is April 9, when a light frost later than that day occurs just 10 % of the time. The 50 % date, March 3, indicates a 50 % chance of a light frost later than this date, while January 31 represents a 90 % gamble for early planting. The hard-frost 50 % dates are January 27 in spring and December 7 in fall, and a hard frost matters more than a light frost because its lower temperature can damage plant tissue more severely.

How to read the probabilities

The dates are probabilities from 30 years of weather, not a forecast for this year.

  • Spring: "10% after April 9" means that in about one spring out of ten a frost still happens after that date. The 90% date is the earliest: a frost after it happens in most years.
  • Fall: "10% before November 7" means that in about one fall out of ten the first frost arrives before that date.
  • 50% is the typical date: half of the years are earlier, half are later.
  • A light frost (32°F) damages tender plants; a hard frost (28°F) also stops most hardy vegetables.

Nearby weather stations

Map of weather stations near Redding, CANumbered nearest stations: 1 — near Lewiston, CA — 30 mi; 2 — near Dunsmuir, CA — 46 mi; 3 — Chester, CA — 58 mi; 4 — near Greenville, CA — 68 mi; 5 — near Redwood Valley, CA — 91 mi.CA50 mi · 80 km1. near Lewiston, CA — 30 mi12. near Dunsmuir, CA — 46 mi23. Chester, CA — 58 mi34. near Greenville, CA — 68 mi45. near Redwood Valley, CA — 91 mi5
  1. near Lewiston, CA 30 mi (48 km)
  2. near Dunsmuir, CA 46 mi (74 km)
  3. Chester, CA 58 mi (93 km)
  4. near Greenville, CA 68 mi (110 km)
  5. near Redwood Valley, CA 91 mi (147 km)

Sources

* Hardiness zone 9a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 40.5175, -122.2986.