Climate and Average Weather Year Round in Batu Indonesia

In Batu, the wet season is oppressive and overcast, the dry season is muggy and partly cloudy, and it is warm year round. Over the course of the year, the temperature typically varies from 60°F to 82°F and is rarely below 56°F or above 86°F.

Based on the tourism score, the best time of year to visit Batu for warm-weather activities is from mid May to early October.

The temperature in Batu varies so little throughout the year that it is not entirely meaningful to discuss hot and cold seasons.

In Batu, 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 Batu begins around May 3 and lasts for 5.4 months, ending around October 14.

The clearest month of the year in Batu is August, during which on average the sky is clear, mostly clear, or partly cloudy 45% of the time.

The cloudier part of the year begins around October 14 and lasts for 6.6 months, ending around May 3.

The cloudiest month of the year in Batu is January, during which on average the sky is overcast or mostly cloudy 90% 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 Batu varies very significantly throughout the year.

The wetter season lasts 5.4 months, from November 14 to April 26, with a greater than 35% chance of a given day being a wet day. The month with the most wet days in Batu is February, with an average of 18.8 days with at least 0.04 inches of precipitation.

The drier season lasts 6.6 months, from April 26 to November 14. The month with the fewest wet days in Batu is August, with an average of 1.3 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 Batu is February, with an average of 18.8 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 67% on February 1.

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. Batu experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Batu. The month with the most rain in Batu is January, with an average rainfall of 10.9 inches.

The month with the least rain in Batu is August, with an average rainfall of 0.4 inches.

The length of the day in Batu does not vary substantially over the course of the year, staying within 35 minutes of 12 hours throughout. In 2024, the shortest day is June 21, with 11 hours, 40 minutes of daylight; the longest day is December 21, with 12 hours, 35 minutes of daylight.

The earliest sunrise is at 5:00 AM on November 15, and the latest sunrise is 44 minutes later at 5:44 AM on July 16. The earliest sunset is at 5:18 PM on May 24, and the latest sunset is 38 minutes later at 5:56 PM on January 30.

Daylight saving time (DST) is not observed in Batu 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.

Batu experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 9.9 months, from September 25 to July 22, during which time the comfort level is muggy, oppressive, or miserable at least 61% of the time. The month with the most muggy days in Batu is March, with 30.9 days that are muggy or worse.

The month with the fewest muggy days in Batu is August, with 15.4 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 Batu experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 4.6 months, from June 8 to October 29, with average wind speeds of more than 5.9 miles per hour. The windiest month of the year in Batu is August, with an average hourly wind speed of 7.7 miles per hour.

The calmer time of year lasts for 7.3 months, from October 29 to June 8. The calmest month of the year in Batu is March, with an average hourly wind speed of 4.3 miles per hour.

The predominant average hourly wind direction in Batu varies throughout the year.

The wind is most often from the east for 4.5 months, from March 17 to August 1, with a peak percentage of 71% on May 13. The wind is most often from the south for 4.6 months, from August 1 to December 20, with a peak percentage of 63% on September 26. The wind is most often from the west for 2.9 months, from December 20 to March 17, with a peak percentage of 52% on January 1.

Batu 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 6.4 months, from November 15 to May 26, with an average temperature above 83°F. The month of the year in Batu with the warmest water is April, with an average temperature of 84°F.

The time of year with cooler water lasts for 2.3 months, from July 17 to September 28, with an average temperature below 80°F. The month of the year in Batu with the coolest water is August, with an average temperature of 80°F.

To characterize how pleasant the weather is in Batu 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 Batu for general outdoor tourist activities is from mid May to early October, with a peak score in the first week of August.

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 Batu for hot-weather activities are from mid April to mid June and from mid October to early November, with a peak score in the third week of May.

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 Batu 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 some seasonal variation over the course of the year.

The brighter period of the year lasts for 2.3 months, from August 13 to October 22, with an average daily incident shortwave energy per square meter above 6.4 kWh. The brightest month of the year in Batu is September, with an average of 6.9 kWh.

The darker period of the year lasts for 4.6 months, from November 27 to April 13, with an average daily incident shortwave energy per square meter below 4.9 kWh. The darkest month of the year in Batu is February, with an average of 4.4 kWh.

For the purposes of this report, the geographical coordinates of Batu are -7.870 deg latitude, 112.528 deg longitude, and 2,890 ft elevation.

The topography within 2 miles of Batu contains very significant variations in elevation, with a maximum elevation change of 1,883 feet and an average elevation above sea level of 2,993 feet. Within 10 miles contains very significant variations in elevation (9,442 feet). Within 50 miles also contains extreme variations in elevation (12,073 feet).

The area within 2 miles of Batu is covered by cropland (58%), trees (18%), and shrubs (11%), within 10 miles by trees (51%) and cropland (25%), and within 50 miles by trees (32%) and cropland (29%).