Climate and Average Weather Year Round in Koumac New Caledonia

In Koumac, the summers are warm, oppressive, wet, and mostly cloudy; the winters are short, comfortable, and mostly clear; and it is windy year round. Over the course of the year, the temperature typically varies from 62°F to 86°F and is rarely below 58°F or above 89°F.

Based on the tourism score, the best time of year to visit Koumac for warm-weather activities is from early July to early December.

The hot season lasts for 3.5 months, from December 10 to March 27, with an average daily high temperature above 83°F. The hottest month of the year in Koumac is February, with an average high of 86°F and low of 75°F.

The cool season lasts for 2.9 months, from June 14 to September 11, with an average daily high temperature below 77°F. The coldest month of the year in Koumac is July, with an average low of 63°F and high of 75°F.

In Koumac, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Koumac begins around June 7 and lasts for 6.0 months, ending around December 7.

The clearest month of the year in Koumac is September, during which on average the sky is clear, mostly clear, or partly cloudy 77% of the time.

The cloudier part of the year begins around December 7 and lasts for 6.0 months, ending around June 7.

The cloudiest month of the year in Koumac is February, during which on average the sky is overcast or mostly cloudy 62% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Koumac varies significantly throughout the year.

The wetter season lasts 3.8 months, from December 23 to April 16, with a greater than 25% chance of a given day being a wet day. The month with the most wet days in Koumac is February, with an average of 11.6 days with at least 0.04 inches of precipitation.

The drier season lasts 8.2 months, from April 16 to December 23. The month with the fewest wet days in Koumac is September, with an average of 3.1 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Koumac is February, with an average of 11.6 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 41% on February 28.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Koumac experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Koumac. The month with the most rain in Koumac is February, with an average rainfall of 6.2 inches.

The month with the least rain in Koumac is September, with an average rainfall of 0.9 inches.

The length of the day in Koumac varies over the course of the year. In 2024, the shortest day is June 21, with 10 hours, 53 minutes of daylight; the longest day is December 21, with 13 hours, 23 minutes of daylight.

The earliest sunrise is at 5:13 AM on November 27, and the latest sunrise is 1 hour, 27 minutes later at 6:39 AM on July 5. The earliest sunset is at 5:29 PM on June 5, and the latest sunset is 1 hour, 20 minutes later at 6:49 PM on January 17.

Daylight saving time (DST) is not observed in Koumac during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Koumac experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 7.9 months, from October 12 to June 8, during which time the comfort level is muggy, oppressive, or miserable at least 32% of the time. The month with the most muggy days in Koumac is March, with 29.8 days that are muggy or worse.

The month with the fewest muggy days in Koumac is August, with 3.4 days that are muggy or worse.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Koumac experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.2 months, from February 24 to August 30, with average wind speeds of more than 12.0 miles per hour. The windiest month of the year in Koumac is May, with an average hourly wind speed of 12.8 miles per hour.

The calmer time of year lasts for 5.9 months, from August 30 to February 24. The calmest month of the year in Koumac is December, with an average hourly wind speed of 11.3 miles per hour.

The predominant average hourly wind direction in Koumac is from the east throughout the year.

Koumac is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.4 months, from December 29 to April 11, with an average temperature above 81°F. The month of the year in Koumac with the warmest water is February, with an average temperature of 82°F.

The time of year with cooler water lasts for 3.5 months, from June 28 to October 10, with an average temperature below 76°F. The month of the year in Koumac with the coolest water is August, with an average temperature of 74°F.

To characterize how pleasant the weather is in Koumac throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Koumac for general outdoor tourist activities is from early July to early December, with a peak score in the last week of September.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Koumac for hot-weather activities are from mid March to late April and from early November to late January, with a peak score in the second week of December.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Temperatures in Koumac are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.

The brighter period of the year lasts for 3.9 months, from September 30 to January 28, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest month of the year in Koumac is November, with an average of 7.4 kWh.

The darker period of the year lasts for 2.9 months, from May 5 to August 1, with an average daily incident shortwave energy per square meter below 4.7 kWh. The darkest month of the year in Koumac is June, with an average of 4.0 kWh.

For the purposes of this report, the geographical coordinates of Koumac are -20.567 deg latitude, 164.283 deg longitude, and 3 ft elevation.

The topography within 2 miles of Koumac contains only modest variations in elevation, with a maximum elevation change of 308 feet and an average elevation above sea level of 42 feet. Within 10 miles contains only modest variations in elevation (3,507 feet). Within 50 miles also contains extreme variations in elevation (5,341 feet).

The area within 2 miles of Koumac is covered by water (53%), trees (20%), and cropland (17%), within 10 miles by water (60%) and trees (26%), and within 50 miles by water (85%) and trees (11%).