Solomon Islands climate: average weather, temperature, precipitation, best time

Index

Introduction - Honiara
Cyclones
Best Time
What to pack

Introduction

The Solomon Islands, located in the Pacific Ocean south of the Equator and east of Papua New Guinea, have an equatorial climate, that is, hot, humid and rainy all year round, so much so that they are covered by rainforests.
Temperatures are stable throughout the year: highs are around 30/31 °C (86/88 °F) from November to April, when the warmer and wetter winds from the north-west predominate, while they drop slightly from May to October, when the south-east trade winds, relatively cooler, prevail.
Rainfall is definitely abundant, since it ranges from 3,000 to 3,500 millimeters (118 to 138 inches) per year on the flat islands, which are the majority, and it's well distributed throughout the year, even though it reaches a peak from January to March, and decreases slightly from May to November, when, however, it remains around 200/250 mm (8/10 in) per month. On the islands that have some elevations in the interior, the rainfall is more abundant on the slopes exposed to the wind and less abundant on the sheltered slopes. In particular, on the island of Guadalcanal, there are volcanoes such as Mount Popomanaseu, 2,335 meters (7,661 feet) high, which protect the northern slopes from the trade winds during the cooler season. So, in Honiara, on the north side, less than 150 mm (6 in) of rain fall from May to October; here, precipitation amounts to "only" 2,200 mm (87 in) per year, with a maximum in March, which is typically the wettest month on all the islands.
Another mountainous island is Kolombangara, where lies Mount Veve, 1,768 meters (5,801 feet) high: here too, there is a difference in the period of the trade winds, between the north side, more sheltered, and the south side, more exposed to the winds that are able to produce rain clouds.

Honiara

In Honiara, the capital, the daytime temperatures are stable, since it is located on the north coast of the island of Guadalcanal, where, as mentioned, there are elevations in the interior that protect it from the south-east trade winds. Here are the average temperatures.

Honiara - Average temperatures
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Min (°C)	23	23	22	22	22	21	21	21	21	22	22	22
Max (°C)	30	30	30	30	30	30	30	30	30	30	30	30
Min (°F)	73	73	72	72	72	70	70	70	70	72	72	72
Max (°F)	86	86	86	86	86	86	86	86	86	86	86	86

As mentioned, Honiara is less rainy than the south side and the flat islands in the austral winter (May to October). Here is the average precipitation in Honiara.

Honiara - Average precipitation
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Prec.(mm)	280	300	330	215	140	100	115	115	115	150	165	235	2255
Prec.(in)	11	11.8	13	8.5	5.5	3.9	4.5	4.5	4.5	5.9	6.5	9.3	88.8
Days	20	20	22	18	17	15	17	15	16	16	16	19	211

The amount of sunshine on the Solomons is not great, nor poor; it's fairly uniform throughout the year, with a few hours of sunshine, but also frequent cloud formation, which may lead to showers or thunderstorms. Here are the average sunshine hours per day in Honiara.

Honiara - Sunshine
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Hours	6	6	6	6	6	6	5	6	6	6	6	6

The sea on the Solomon Islands is warm enough to swim in all year round, as we can see in the following table.

Honiara - Sea temperature
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Temp (°C)	29	29	29	29	29	28	28	28	28	28	29	29
Temp (°F)	84	84	84	84	84	82	82	82	82	82	84	84

Tropical cyclones

The Solomon Islands are located at the north-western boundary of the area where tropical cyclones of the South Pacific form; therefore, they are affected with a lower frequency than other areas of the South Pacific. In particular, the least affected provinces are usually the north-western ones (Choiseul, Western Province, Isabel), while the most affected are the south-eastern ones (Makira-Ulawa, Rennell and Bellona, Temotu).
Cyclones are generally formed from November to mid-May, but since the sea is always warm, they have sometimes formed outside of this period, as happened for example with Cyclone Raquel in late July 2015, or with Cyclone Xavier, which affected the southeastern province of Temotu (in the group of the Santa Cruz Islands) in late October 2006.

Best Time

The best time to visit the Solomon Islands is from June to October, since it is the least muggy and rainy, bearing in mind, however, that showers are frequent even in this period, and they may even be abundant on the south-facing slopes, especially on the mountainous islands. In July, the rains often increase compared with the other months of this period, except on the northern slopes of mountainous islands such as Guadalcanal. In the period from June to October, the north side of Guadalcanal, where Honiara is located, is by far the most sheltered area of the whole archipelago.

What to pack