Tulsa, Oklahoma, United States

Frost dates for Tulsa

The full distribution rather than a single date. Every figure below is a percentile of 30 years of daily minimum temperatures at this location, expressed as the date it fell on.

Median last spring frost

29 March

Half of years are later than this. Not a planting date.

Median first autumn frost

8 November

The far end of the outdoor season.

Frost-free season

224 days

Between those two dates in a median year.

Last and first frost by severity

Read a row as: in this fraction of years, the last frost of spring had already happened by this date. The 90% column is the cautious planting date; the 10% column is the gamble.

Light frost — nights at or below 0°C (32°F). Air temperature reaches freezing. Kills basil, beans and unhardened tomatoes; hardy crops shrug it off.
Frost	1 year in 10	Median	9 years in 10	Earliest	Latest
Last of spring	13 Mar	29 Mar	15 Apr	7 Mar	24 Apr
First of autumn	27 Oct	8 Nov	24 Nov	10 Oct	8 Dec
Frost-free days	256	224	195	every year on record saw this

Moderate frost — nights at or below -2.2°C (28°F). Damages half-hardy plants and most blossom. This is the threshold that decides a fruit crop.
Frost	1 year in 10	Median	9 years in 10	Earliest	Latest
Last of spring	27 Feb	15 Mar	8 Apr	25 Feb	16 Apr
First of autumn	31 Oct	21 Nov	5 Dec	27 Oct	8 Dec
Frost-free days	281	251	206	every year on record saw this

Hard frost — nights at or below -4.4°C (24.1°F). Ground freezes and even hardy crops check their growth. Effectively the end of the outdoor year.
Frost	1 year in 10	Median	9 years in 10	Earliest	Latest
Last of spring	14 Feb	8 Mar	24 Mar	4 Feb	29 Mar
First of autumn	11 Nov	28 Nov	19 Dec	31 Oct	24 Dec
Frost-free days	308	265	232	every year on record saw this

Dates in the southern hemisphere are computed on a growing year that starts in July, which is why "last of spring" falls where it should rather than in the middle of the calendar.

Chance of frost, week by week

Chance of at least one air frost during each week of the year, measured across the full record. The flat stretch in the middle is your frost-free season.

Temperature through the year

Mean monthly temperature across the record. Months shown in blue average at least one air frost.

Monthly means and average number of frost nights.
Month	Mean low	Mean high	Frost nights
January	-2.6°C	8.2°C	22.9
February	-0.8°C	11°C	16.9
March	4.1°C	16.7°C	7
April	8.9°C	21.6°C	1
May	14.9°C	26.1°C	0
June	20.1°C	30.9°C	0
July	22.7°C	34.6°C	0
August	22.3°C	34.8°C	0
September	17.7°C	30.6°C	0
October	10.5°C	23.5°C	0.5
November	4°C	16°C	6.8
December	-1.1°C	9.8°C	19.3

Turn these dates into a planting calendar →

Nearby

Compare with places close by

Oklahoma City Zone 7b 157 km Last frost 28 Mar First 10 Nov Norman Zone 8a 167 km Last frost 25 Mar First 15 Nov Wichita Zone 7a 209 km Last frost 12 Apr First 29 Oct