Safe to Plant

Jepara, Central Java, Indonesia

Does it frost in Jepara?

No. Across 29 years of daily minimum temperatures for this location, not one night reached freezing — not at the light-frost threshold, and so not at any of the colder ones either. There is no last spring frost here to plant after and no first autumn frost to harvest before.

Frost nights on record

None

In all 29 years of the record.

Coldest night ever recorded

22.9°C (73.2°F)

The single lowest reading in the record.

Margin above freezing

22.9°C (41.2°F)

How far the record low still sat above 0°C.

How close it has come

"Never" is worth more when you can see the margin. The coldest night in the entire record for Jepara reached 22.9°C (73.2°F), which is still 22.9°C (41.2°F) above freezing. That is the one-in-a-generation night, not a typical one.

The cold end of the record. A frost would need the first row to reach 0°C; it never has.
Measure Temperature What it means
Coldest night on record 22.9°C The lowest single reading in 29 years.
Coldest night of an average year 23.8°C Each year has a coldest night; this is their average. It is the figure the hardiness zone is built from.
Coolest month's average night 25.3°C An ordinary night in the coolest part of the year.

The gap between those first two rows — 0.9°C (1.7°F) — is how much colder the exceptional year runs than the average one. A wide gap means the record is carried by rare events; a narrow one means the climate here simply does not reach freezing.

The nearest place that does freeze

There is no town in this dataset within roughly 2,500 km of Jepara with a frost in its record. Frost is not a marginal risk here or a matter of a cold year — it is absent from this whole part of the world, and nothing in a planting plan for Jepara needs to allow for it.

What sets the season instead

Everywhere that freezes, the calendar is written by frost: sow after the last one, harvest before the first. With that constraint gone, the limits here are heat, daylength and rain. 2 months of the year average a daily high at or above 30°C, peaking in October around 28.5°C (83.3°F), which is where cool-season crops such as lettuce, peas and brassicas struggle — they bolt in heat rather than die in cold, so the sowing window closes at the warm end of the year rather than the cold one.

Accumulated warmth is the honest substitute for a season length here: 6,254 growing degree days above 10°C across the full twelve months, because there is no frost to close the count at either end. Elsewhere that total has to be earned between two frost dates.

See what to sow in Jepara, month by month →

Every month of the year, above freezing

The last column is the evidence for everything above it: the average number of nights per month at or below 0°C, which is zero in every row.

J
F
M
A
M
J
J
A
S
O
N
D

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 26.5°C 27.9°C 0
February 26.3°C 27.7°C 0
March 26.6°C 28.2°C 0
April 26.9°C 28.7°C 0
May 26.8°C 29.2°C 0
June 26.2°C 29°C 0
July 25.4°C 29.2°C 0
August 25.3°C 29.8°C 0
September 26°C 30.5°C 0
October 26.7°C 30.3°C 0
November 27°C 29.4°C 0
December 26.7°C 28.4°C 0

Figures are derived from NASA POWER daily minimum and maximum temperatures at this location. A frost night is counted whenever the daily minimum reaches 0°C or below. See how these numbers are worked out.