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Trincomalee weather by month: averages, rainfall & climate trends

Warmth in Trincomalee is remarkably steady: only 3.9°C separates the warmest month from the coolest, so there is no cold season to speak of. Most of the year's rain is packed into the months from October to January. Trincomalee weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+1.5°Chigh above average

31° / 26°Today
30° / 25°Average
see today in detail →

How it's changed

+0.9°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49209days above 30°C a year now (2016–2025) · 185 in the 1940sdays above 30°C · 185 in the 1940s+0.9°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 137 mmhigh 27°low 24°February, rain 74 mmhigh 27°low 24°March, rain 52 mmhigh 29°low 25°April, rain 61 mmhigh 31°low 26°May, rain 55 mmhigh 33°low 27°June, rain 17 mmhigh 33°low 27°July, rain 33 mmhigh 33°low 26°August, rain 44 mmhigh 33°low 26°September, rain 63 mmhigh 32°low 26°October, rain 170 mmhigh 30°low 25°November, rain 273 mmhigh 28°low 25°December, rain 270 mmhigh 27°low 24°wettest month November, 273 mm · 1,247 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

26.5°

33°feels like
93%humidity
25°dew point
6 km/hfrom SW
UV index1.3
sunrise05:52sunset17:46day length11h 54m
TodayThunderstorm with hail31°26°
ThuOvercast33°25°
FriOvercast34°25°
SatOvercast33°25°
SunOvercast33°26°
MonOvercast32°26°
TueOvercast32°26°

On this date: October 21

Today (forecast)
31° / 26°
Average for October 21
30° / 25°

High above average · +1.5°C

  • Highest since 1940: 33.2° · 1974
  • Lowest since 1940: 24.0° · 1971
  • One year ago: 28° / 25°

Every October 21 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 21 on record (n = 86). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Trincomalee is sampled from the ECMWF ERA5 reanalysis at 8.58°N, 81.23°E, with daily records since 1940.

Coordinates
8.58°N, 81.23°E
Time zone
Asia/Colombo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

25 of the last 30 days were warmer than the historical average for that date. Average difference: +0.7°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

The year peaks in May, at around 32.8°C by mid-afternoon, with nights around 26.8°C. At the other extreme, January brings afternoon highs of about 26.7°C and typical overnight lows of 24.1°C.

The yearly total for Trincomalee comes to about 1,247 mm; monthly amounts range from 17 mm in June up to 273 mm in November.

Over the full record (since 1940), the annual mean temperature in Trincomalee has risen by 0.9°C between its first decade and its last. Recent years have brought more rain as well. The last decade sits roughly 16% over the long-term average.

Climate graph (climograph)

May is the warmest month, January the coolest: a yearly swing of 4°C. Wettest month: November (~273 mm). Whole year averages ~1,247 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Trincomalee month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainDaylightHighestLowest
January26.7°24.1°137 mm11.6 h29.1° (2016)19.8° (1980)
February27.5°24.3°74 mm11.7 h30.8° (1950)19.6° (1957)
March29.1°25.0°52 mm11.9 h34.9° (1953)20.7° (1999)
April31.1°26.1°61 mm12.2 h36.6° (1973)23.8° (1993)
May32.8°26.8°55 mm12.4 h36.7° (1979)24.1° (1972)
June32.9°26.7°17 mm12.5 h37.2° (1979)24.4° (1943)
July32.6°26.4°33 mm12.5 h35.2° (2024)24.1° (1942)
August32.5°26.2°44 mm12.3 h35.7° (2023)23.8° (1965)
September32.3°26.0°63 mm12.0 h35.8° (1952)24.2° (1994)
October30.4°25.3°170 mm11.8 h35.1° (1946)22.8° (1976)
November28.1°24.7°273 mm11.6 h32.7° (2025)21.1° (2016)
December27.0°24.3°270 mm11.5 h31.5° (2024)20.9° (2022)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +0.9°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.12°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Jun–Aug is warming fastest: +0.15°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 185.1 early in the record → 208.6 recently. Frost days: 0 → 0.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 1979, coldest in 1957: 37.2°C / 19.6°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,247 mm/year on average. Last decade: +16% vs that average. Long-term trend: +55 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Trincomalee

Which is the warmest month in Trincomalee?
On long-term average, the warmest month in Trincomalee is May (mean daily temperature of about 29.3°C) and the coolest is January (about 25.4°C).
How does today's temperature in Trincomalee compare to the historical average?
On October 21, 2026, Trincomalee is forecast to reach a high of 31.0°C and a low of 25.5°C. The long-term average for this date (the full record since 1940) is a high of 29.5°C and a low of 25.1°C, so today's high is 1.5°C warmer than that average.
How much has Trincomalee warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Trincomalee is about 0.9°C warmer.
How much does it rain in Trincomalee?
Trincomalee receives about 1,247 mm of precipitation per year on long-term average, with November typically the wettest month.
What is the average temperature in Trincomalee?
Over the full record (since 1940), the annual mean temperature in Trincomalee is about 27.5°C. The warmest month is May and the coolest is January.
What are the average temperatures in Trincomalee by month?
Average daily highs and lows for each month in Trincomalee (°C, full record since 1940): January 27°/24°, February 27°/24°, March 29°/25°, April 31°/26°, May 33°/27°, June 33°/27°, July 33°/26°, August 33°/26°, September 32°/26°, October 30°/25°, November 28°/25°, December 27°/24°.

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