Frost dates for Scappoose Ind Airport, Oregon
Half of years have their last spring frost by April 10, but 1 year in 10 still frosts after May 1.
A frost date is really a percentile from 30 years of records at a nearby weather station: in about half of years a frost still comes after the median date. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
How often a frost still comes on or after each date.
- 1 year in 10
- May 1
- 1 year in 5
- April 25
- 3 years in 10
- April 19
- 2 years in 5
- April 14
- Half of years (the median)
- April 10
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 16
- 1 year in 5
- October 22
- 3 years in 10
- October 26
- 2 years in 5
- October 30
- Half of years (the median)
- November 2
- Growing season
- about 209 days
- Hardiness zone nearby
- 8b
- Summer days
- a usual high of about 26 °C79 °F
- Lettuce and spinach run to seed
- July to September, in hot, long days (how we know)
Summer and rain
A growing garden needs about 25 mm1 in of water a week, rain and watering together. Here is what a normal month brings.
- Nearly every drop is yours
- July to August: rain brings less than a quarter of the water a growing garden needs, about 25 mm1 in a week (how we know)
Month by month
- January
- high ~8 °C47 °F · low ~1 °C34 °F · rain ~166 mm6.5 in
- February
- high ~11 °C51 °F · low ~1 °C34 °F · rain ~117 mm4.6 in
- March
- high ~14 °C56 °F · low ~3 °C37 °F · rain ~115 mm4.5 in
- April
- high ~16 °C61 °F · low ~4 °C40 °F · rain ~78 mm3.1 in
- May
- high ~20 °C68 °F · low ~8 °C46 °F · rain ~63 mm2.5 in
- June
- high ~23 °C73 °F · low ~10 °C51 °F · rain ~35 mm1.4 in
- July
- high ~27 °C81 °F · low ~12 °C54 °F · rain ~12 mm0.5 in
- August
- high ~28 °C82 °F · low ~12 °C54 °F · rain ~13 mm0.5 in
- September
- high ~25 °C76 °F · low ~10 °C50 °F · rain ~40 mm1.6 in
- October
- high ~18 °C64 °F · low ~6 °C43 °F · rain ~91 mm3.6 in
- November
- high ~11 °C53 °F · low ~3 °C37 °F · rain ~159 mm6.3 in
- December
- high ~8 °C46 °F · low ~1 °C34 °F · rain ~184 mm7.2 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Scappoose Ind Airport station (listed by NOAA as Scappoose Ind Ap, USW00004201), at 45.77, -122.86. These are that station’s own records, unshifted. The further your garden is from it, the less exactly they describe your ground. The planner finds the nearest station to your garden and lowers its confidence with distance, so no number is presented as if it were measured in your garden.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a few hundred feet away does not. No table can know that about your garden. A few seasons of your own logged frosts can.
ZIP codes nearest this station
97056, 97133, 97231, 98642.
When do I plant? · Where the dates come from
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