Sirjan, Kerman, Iran

Frost dates for Sirjan

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

14 March

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

Median first autumn frost

3 December

The far end of the outdoor season.

Frost-free season

264 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	26 Feb	14 Mar	25 Mar	9 Feb	14 Apr
First of autumn	20 Nov	3 Dec	17 Dec	7 Nov	27 Dec
Frost-free days	294	264	240	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	10 Feb	1 Mar	14 Mar	23 Jan	27 Mar
First of autumn	27 Nov	15 Dec	28 Dec	22 Nov	31 Dec
Frost-free days	321	290	258	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	18 Jan	10 Feb	3 Mar	8 Jan	20 Mar
First of autumn	8 Dec	21 Dec	29 Dec	4 Dec	31 Dec
Frost-free days	345	314	280	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	-0.6°C	13.1°C	17.7
February	0.9°C	15.5°C	11
March	4.4°C	19.8°C	3.7
April	9.4°C	25.3°C	0
May	14.5°C	31.3°C	0
June	18.9°C	36.3°C	0
July	21°C	37.5°C	0
August	19.1°C	35.9°C	0
September	16.3°C	33°C	0
October	11.8°C	27.2°C	0
November	5.7°C	19.8°C	1.1
December	1.5°C	15.4°C	9.2

Turn these dates into a planting calendar →