The best times to visit Sumatra for ideal weather are
July 16th to August 5th
based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.
Sumatra Travel Guide
Other Sumatra Travel Info
Weather in Sumatra
Average temperatures in Sumatra vary barely at all. Considering humidity, temperatures feel hot all year with a chance of rain throughout most of the year. The area is far less temperate than some — in the bottom 1 percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Sumatra, the hottest months are May, April, and then March. See average monthly temperatures below. The warmest time of year is generally early to mid May where highs are regularly around 89.2°F (31.8°C) with temperatures rarely dropping below 74.7°F (23.7°C) at night.
Sumatra Temperatures (Fahrenheit)
Sumatra Temperatures (Celsius)
The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.
Sumatra Perceived Temperature (F)
Sumatra Perceived Temperature (C)
Average Sumatra Temperatures by Month
Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.
|Month||Avg. High (°F)||Avg. Mean (°F)||Avg. Low (°F)|
|Month||Avg. High (°C)||Avg. Mean (°C)||Avg. Low (°C)|
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Sumatra are May, July, and then January. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around late July. For example, on the week of July 23rd there is 1 day of precipitation on average. By contrast, it’s most likely to rain or snow in early November with an average of 4 days of significant precipitation the week of November 5th.
When can you find snow in Sumatra? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.
Chance of Precipitation
The graph below shows the % chance of rainy and snowy days in Sumatra.
Snow on the Ground
The graph below shows the average snow on the ground in Sumatra (in).
Average Rain and Snow by Month
|Month||Daily Chance of Rain||Average Snow Depth (in)||Total Precipitation (in)|
|Month||Daily Chance of Rain||Average Snow Depth (cm)||Total Precipitation (cm)|
Humidity and Wind
Sumatra has some extremely humid months, and high humidity throughout the year. The least humid month is February (76.7% relative humidity), and the most humid month is November (82.6%).
Wind in Sumatra is usually extremely calm. The windiest month is September, followed by August and December. September’s average wind speed of around 2.6 knots (3 MPH or 4.8 KPH) is considered “light air.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in mid to late August where average top sustained speeds reach 9.2 knots, which is considered a gentle breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Sumatra.
The graph below shows wind speed (max and average) in knots.
Average Wind Speeds
Show Wind Speeds
All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.
|Month||Avg. Wind||Avg. Wind Feel||Sustained High Wind||High Wind Feel|
|Jan||2.3||Barely noticeable||8||Gentle breeze|
|Feb||2.4||Barely noticeable||7.7||Gentle breeze|
|Mar||2.4||Barely noticeable||7.7||Gentle breeze|
|Apr||2.4||Barely noticeable||7.7||Gentle breeze|
|May||2.3||Barely noticeable||7.6||Gentle breeze|
|Jun||2.4||Barely noticeable||7.9||Gentle breeze|
|Jul||2.2||Barely noticeable||7.7||Gentle breeze|
|Aug||2.5||Barely noticeable||8.1||Gentle breeze|
|Sep||2.6||Barely noticeable||8||Gentle breeze|
|Oct||2.4||Barely noticeable||7.4||Gentle breeze|
|Nov||2.4||Barely noticeable||8||Gentle breeze|
|Dec||2.4||Barely noticeable||8.1||Gentle breeze|
Show Relative Humidity by Month
|Month||Avg. Relative Humidity|
Is it Safe to Travel to Sumatra?
Our best data indicates this area is somewhat safe, but with extra warnings in a few regions. As of Oct 07, 2019 there are travel warnings and regional advisories for Indonesia; exercise a high degree of caution and avoid some areas. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Sep 20, 2019.
The Busiest and Least Crowded Months
The busiest month for tourism in Sumatra, Indonesia is December, followed by November and January. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Sumatra in February. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
Overall Sumatra Travel Experience by Season
Fall (March through May)
Humidity and temperatures combine to make this season feel warm. Highs range from 89.2°F (31.8°C) and 87.8°F (31°C) with similar temperatures in the later months. Rain is somewhat common with 5 to 10 days of significant precipitation per month. Fall is the second busiest for tourism, which makes it a good time for those looking for things to do.
Winter (June through August)
The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see the least precipitation with 5 to 9 days of precipitation per month. June – August is the slowest season for tourism in Sumatra, so lodging and other accommodations may cost less than usual.
Spring (September through November)
Spring daily highs range from 87.6°F (30.9°C) and 86.3°F (30.2°C), which will feel very nice given the humidity and wind. It rains or snows a good amount: 9 to 16 days per month. Tourism is fairly slow during these months due to the weather, so hotels may be lower priced.
Summer (December through February)
Weather is perfect this time of year in Sumatra to be enjoyable for warm weather travelers. The average high during this season is between 88.5°F (31.4°C) and 87°F (30.6°C). On average, it rains or snows a fair amount: 7 to 13 times per month. These times of year are the busiest with tourists.