Siayan, Philippines experiences average highs of 29°C (84°F) and lows of 25°C (77°F) throughout the year. Rainfall is frequent, averaging about 26 rainy days per month. Sunshine is abundant, averaging about 9 hours per day. High humidity combined with warm temperatures produces a tropical feel year-round. Average highs have stayed broadly stable across the available records.
Siayan, Philippines Weather & Climate 2026
Monthly climate averages for Siayan, Philippines. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Dec 
Wetter season: May–Oct At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
2.4/10
Best: February
UV Index
8
High
Temperature 29°C / 25°C
Feels Like 36°C / 30°C
Rainy Days 26
Rainfall 321 mm
Sunshine 9 h
Humidity 87%
Wind Speed 11 km/h
Dew Point 25°C
Hottest Month
30°C
April
Avg Low 25°C
Rain 23 days
Coldest Month
24°C
February
Avg High 28°C
Rain 17 days
Driest Month
17 days
February
Avg High 28°C
Avg Low 24°C
Windiest Month
15 km/h
February (Gusts 37)
Sea Temperature
27°C – 30°C
Warmest water: June (
30.3°C
)
Worst Time to Visit
Consider avoiding May, August, September, October due to extreme heat, heavy rainfall, oppressive humidity.
Sun Position
Sunrise 05:30
Daylight 12.6h
Sunset 18:06
Live conditions —
Siayan on the map · live conditions
Siayan, Philippines
- Continent
- Asia
- Country
- Philippines
- City
- Siayan
- Population
- 4.9K
- Coordinates
- 8.27°, 123.10°
Seasonal Breakdown
Spring
Mar–May
Avg High 30°C
Avg Low 25°C
Rain 24 days/mo
Summer
Jun–Aug
Avg High 29°C
Avg Low 25°C
Rain 29 days/mo
Autumn
Sep–Nov
Avg High 29°C
Avg Low 25°C
Rain 29 days/mo
Winter
Dec–Feb
Avg High 28°C
Avg Low 25°C
Rain 23 days/mo
1/3 best months
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
High Low Shaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 28°C / 25°C . Feb: 28°C / 24°C . Mar: 29°C / 25°C . Apr: 30°C / 25°C . May: 30°C / 25°C . Jun: 29°C / 25°C . Jul: 29°C / 25°C . Aug: 29°C / 25°C . Sep: 29°C / 25°C . Oct: 29°C / 25°C . Nov: 29°C / 25°C . Dec: 29°C / 25°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 248 mm. Feb: 167 mm. Mar: 184 mm. Apr: 199 mm. May: 385 mm. Jun: 451 mm. Jul: 413 mm. Aug: 354 mm. Sep: 420 mm. Oct: 426 mm. Nov: 287 mm. Dec: 322 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 88%. Feb: 86%. Mar: 84%. Apr: 84%. May: 87%. Jun: 88%. Jul: 87%. Aug: 86%. Sep: 87%. Oct: 89%. Nov: 88%. Dec: 89%.
Monthly Wind Speed
Wind Speed Gusts
Bar chart showing monthly wind speed. Jan: 14 km/h . Feb: 15 km/h . Mar: 13 km/h . Apr: 10 km/h . May: 8 km/h . Jun: 8 km/h . Jul: 10 km/h . Aug: 10 km/h . Sep: 10 km/h . Oct: 9 km/h . Nov: 10 km/h . Dec: 11 km/h .
Sunshine
Sunshine
Sunshine: Jan: 9h. Feb: 10h. Mar: 10h. Apr: 11h. May: 10h. Jun: 9h. Jul: 9h. Aug: 9h. Sep: 9h. Oct: 9h. Nov: 9h. Dec: 9h.
Sea Temperature
Sea Temperature swim
Line chart showing monthly sea temperature. Jan: 28°C . Feb: 27°C . Mar: 28°C . Apr: 29°C . May: 30°C . Jun: 30°C . Jul: 30°C . Aug: 30°C . Sep: 30°C . Oct: 30°C . Nov: 30°C . Dec: 29°C .
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 7. Feb: UV 8. Mar: UV 9. Apr: UV 9. May: UV 8. Jun: UV 8. Jul: UV 8. Aug: UV 8. Sep: UV 8. Oct: UV 8. Nov: UV 8. Dec: UV 7.
Monthly Daylight Hours
Daylight 12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall is trending wetter by about 131 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Apr 2025 · 30°C | Apr · 30°C |
| Coldest month | Aug 2025 · 25°C | Feb · 24°C |
| Wettest month | Oct 2025 · 589 mm | Jun · 451 mm |
| Windiest month | Jul 2025 · 13 km/h | Feb · 15 km/h |
Month-by-Month Weather Table
January
Wet 
February best
Fair March
Wet April
Wet May
Wet June
Wet July
Wet August
Wet September
Wet October
Wet November
Wet December
Wet | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 28°C / 25°C | 34°C / 29°C | 23days (248 mm) Wet | 8.6h Good | 88% Very Muggy | 7.3 Very High | Wet | View Details |
| February best | 28°C / 24°C | 34°C / 29°C | 17days (167 mm) Wet | 9.7h Good | 86% Very Muggy | 8 Very High | Fair | View Details |
| March | 29°C / 25°C | 35°C / 30°C | 19days (184 mm) Wet | 10.3h Excellent | 84% Humid | 9 Very High | Wet | View Details |
| April | 30°C / 25°C | 37°C / 31°C | 23days (199 mm) Wet | 10.5h Excellent | 84% Humid | 8.8 Very High | Wet | View Details |
| May | 30°C / 25°C | 37°C / 31°C | 29days (385 mm) Wet | 9.9h Good | 87% Very Muggy | 7.8 Very High | Wet | View Details |
| June | 29°C / 25°C | 36°C / 31°C | 30days (451 mm) Wet | 9h Good | 88% Very Muggy | 7.7 Very High | Wet | View Details |
| July | 29°C / 25°C | 36°C / 30°C | 29days (413 mm) Wet | 8.7h Good | 87% Very Muggy | 7.7 Very High | Wet | View Details |
| August | 29°C / 25°C | 36°C / 30°C | 29days (354 mm) Wet | 9.1h Good | 86% Very Muggy | 8.4 Very High | Wet | View Details |
| September | 29°C / 25°C | 36°C / 30°C | 28days (420 mm) Wet | 8.8h Good | 87% Very Muggy | 8.1 Very High | Wet | View Details |
| October | 29°C / 25°C | 36°C / 30°C | 30days (426 mm) Wet | 8.6h Good | 89% Very Muggy | 8.2 Very High | Wet | View Details |
| November | 29°C / 25°C | 36°C / 30°C | 28days (287 mm) Wet | 9.2h Good | 88% Very Muggy | 7.5 Very High | Wet | View Details |
| December | 29°C / 25°C | 35°C / 30°C | 28days (322 mm) Wet | 8.9h Good | 89% Very Muggy | 7.2 Very High | Wet | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Siayan are February, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Siayan, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Siayan is April, with average daytime highs of 30°C (86°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Siayan is February, with average overnight lows of 24°C (76°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Siayan is June, averaging 451mm of precipitation across 30 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Siayan runs through June, October, May, July, with the heaviest rainfall in June. Based on 10-year averages for Siayan.
Siayan receives approximately 111 sunshine hours per year. The sunniest month is April with around 11 hours. Based on climate data for Siayan.
The least favorable months to visit Siayan are May, August, September, October, primarily due to extreme heat, heavy rainfall, oppressive humidity. For the best conditions, consider February instead.
The annual average UV index in Siayan is 8, classified as high. SPF 30+ sunscreen, sunglasses, and seeking shade between 10:00–16:00 are strongly recommended.
Average humidity in Siayan is 87%, classified as humid. High humidity makes warm temperatures feel significantly hotter — lightweight, breathable clothing is recommended.
Yes — sea temperatures in January, February, March, April, May, June, July, August, September, October, November, December average 29°C (84°F), which is warm and comfortable for swimming and water activities.
Average wind speeds in Siayan are 11 km/h (7 mph). The windiest month is February with peak winds reaching 15 km/h (9 mph) (gusts up to 37 km/h / 23 mph).
Siayan averages 0 clear-sky days per month with overall cloud cover around 86%. The clearest skies occur in April.
The annual average dew point in Siayan is 25°C (77°F), which feels oppressively humid. Expect heavy perspiration during warmer months — stay hydrated and take breaks in air-conditioned spaces.
Siayan has a Tropical Rainforest climate, classified as Af under the Köppen system. Tropical climates are warm year-round with high rainfall and temperatures rarely dropping below 18°C (64°F).
The 'feels like' temperature in Siayan ranges from 30°C (86°F) to 36°C (97°F) on average. Humidity and radiant heat mean it often feels warmer than the thermometer reads, especially in summer months.
June is not the best time to visit Siayan, with a climate score of 2.1/10. Consider visiting during February instead for better conditions.
For June in Siayan, pack Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). With average highs of 29°C (85°F) and 30 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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