Frost dates for Tulsa International Airport, Oklahoma
Half of years have their last spring frost by March 31, but 1 year in 10 still frosts after April 15.
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
- April 15
- 1 year in 5
- April 9
- 3 years in 10
- April 5
- 2 years in 5
- April 2
- Half of years (the median)
- March 31
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 20
- 1 year in 5
- October 26
- 3 years in 10
- October 30
- 2 years in 5
- November 1
- Half of years (the median)
- November 4
- Growing season
- about 220 days
- Hardiness zones nearby
- 7a, 7b
- Summer days
- a usual high of about 33 °C92 °F
- Lettuce and spinach run to seed
- May 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.
- Hot-weather watering
- July to August: days run above 32 °C90 °F and nights stay above 21 °C70 °F, so expect to water daily or every other day (how we know)
Month by month
- January
- high ~9 °C49 °F · low ~-2 °C28 °F · rain ~41 mm1.6 in
- February
- high ~12 °C54 °F · low ~0 °C32 °F · rain ~41 mm1.6 in
- March
- high ~17 °C63 °F · low ~5 °C41 °F · rain ~79 mm3.1 in
- April
- high ~22 °C72 °F · low ~10 °C49 °F · rain ~111 mm4.4 in
- May
- high ~26 °C80 °F · low ~15 °C60 °F · rain ~146 mm5.7 in
- June
- high ~31 °C88 °F · low ~20 °C69 °F · rain ~118 mm4.6 in
- July
- high ~34 °C94 °F · low ~23 °C73 °F · rain ~96 mm3.8 in
- August
- high ~34 °C93 °F · low ~22 °C71 °F · rain ~86 mm3.4 in
- September
- high ~29 °C85 °F · low ~17 °C63 °F · rain ~98 mm3.9 in
- October
- high ~23 °C74 °F · low ~10 °C51 °F · rain ~96 mm3.8 in
- November
- high ~16 °C61 °F · low ~4 °C39 °F · rain ~68 mm2.7 in
- December
- high ~10 °C51 °F · low ~0 °C31 °F · rain ~62 mm2.4 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Tulsa International Airport station (listed by NOAA as Tulsa Intl Ap, USW00013968), at 36.20, -95.89. 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
74015, 74019, 74021, 74036, 74053, 74055, 74070, 74073, 74082, 74103, 74104, 74105…
+20 moreShow fewer
74106, 74107, 74108, 74110, 74112, 74114, 74115, 74116, 74117, 74119, 74120, 74126, 74127, 74128, 74129, 74130, 74134, 74135, 74145, 74146.
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