Siay, Philippines experiences average highs of 29°C (84°F) and lows of 25°C (77°F) throughout the year. Rainfall is frequent, averaging about 24 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.
Siay, Philippines Weather & Climate 2026
Monthly climate averages for Siay, 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
2.3/10
Best: February
UV Index
8
High
Temperature 29°C / 25°C
Feels Like 36°C / 30°C
Rainy Days 24
Rainfall 222 mm
Sunshine 9 h
Humidity 85%
Wind Speed 12 km/h
Dew Point 24°C
Hottest Month
30°C
March
Avg Low25°C
Rain17days
Coldest Month
25°C
January
Avg High30°C
Rain18days
Driest Month
14days
February
Avg High30°C
Avg Low25°C
Windiest Month
13 km/h
July (Gusts 28)
Sea Temperature
30°C – 31°C
Warmest water: May (
31.1°C
)
Worst Time to Visit
Consider avoiding April, May, September, October due to extreme heat, heavy rainfall, oppressive humidity.
Sun Position
Sunrise 05:33
Daylight 12.6h
Sunset 18:07
Live conditions—
Siay on the map · live conditions
Siay, Philippines
- Continent
- Asia
- Country
- Philippines
- City
- Siay
- Population
- 2.4K
- Coordinates
- 7.70°, 122.86°
Seasonal Breakdown
Spring
Mar–May
Avg High 30°C
Avg Low 25°C
Rain 22 days/mo
Summer
Jun–Aug
Avg High 29°C
Avg Low 25°C
Rain 28 days/mo
Autumn
Sep–Nov
Avg High 29°C
Avg Low 25°C
Rain 27 days/mo
Winter
Dec–Feb
Avg High 30°C
Avg Low 25°C
Rain 19 days/mo
1/3 best months
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 30°C / 25°C . Feb: 30°C / 25°C . Mar: 30°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: 30°C / 25°C . Dec: 30°C / 25°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 156 mm. Feb: 106 mm. Mar: 140 mm. Apr: 159 mm. May: 248 mm. Jun: 318 mm. Jul: 304 mm. Aug: 252 mm. Sep: 292 mm. Oct: 293 mm. Nov: 214 mm. Dec: 180 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 83%. Feb: 80%. Mar: 82%. Apr: 84%. May: 87%. Jun: 88%. Jul: 88%. Aug: 88%. Sep: 87%. Oct: 87%. Nov: 86%. Dec: 85%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 12 km/h . Feb: 13 km/h . Mar: 11 km/h . Apr: 10 km/h . May: 10 km/h . Jun: 11 km/h . Jul: 13 km/h . Aug: 13 km/h . Sep: 12 km/h . Oct: 11 km/h . Nov: 10 km/h . Dec: 11 km/h .
Sunshine
Sunshine
Sunshine: Jan: 9h. Feb: 10h. Mar: 11h. Apr: 11h. May: 9h. Jun: 9h. Jul: 9h. Aug: 9h. Sep: 9h. Oct: 9h. Nov: 10h. Dec: 9h.
Sea Temperature
Sea Temperature
Line chart showing monthly sea temperature. Jan: 30°C . Feb: 30°C . Mar: 30°C . Apr: 31°C . May: 31°C . Jun: 30°C . Jul: 30°C . Aug: 30°C . Sep: 30°C . Oct: 30°C . Nov: 30°C . Dec: 30°C .
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 8. 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
Daylight12h 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 88 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Apr 2025 · 30°C | Mar · 30°C |
| Coldest month | Aug 2025 · 25°C | Jan · 25°C |
| Wettest month | Aug 2025 · 419 mm | Jun · 318 mm |
| Windiest month | Jul 2025 · 16 km/h | Jul · 13 km/h |
Month-by-Month Weather Table
January
Wet 
February best
Poor March
Poor 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 | 30°C / 25°C | 36°C / 29°C | 18days (156 mm) Wet | 9.1h Good | 83% Humid | 7.5 Very High | Wet | View Details |
| February best | 30°C / 25°C | 36°C / 29°C | 14days (106 mm) Wet | 10.1h Excellent | 80% Humid | 7.9 Very High | Poor | View Details |
| March | 30°C / 25°C | 37°C / 30°C | 17days (140 mm) Wet | 10.5h Excellent | 82% Humid | 8.8 Very High | Poor | View Details |
| April | 30°C / 25°C | 37°C / 31°C | 22days (159 mm) Wet | 10.5h Excellent | 84% Humid | 8.9 Very High | Wet | View Details |
| May | 30°C / 25°C | 37°C / 31°C | 28days (248 mm) Wet | 9.3h Good | 87% Very Muggy | 8.1 Very High | Wet | View Details |
| June | 29°C / 25°C | 35°C / 30°C | 28days (318 mm) Wet | 8.7h Good | 88% Very Muggy | 7.5 Very High | Wet | View Details |
| July | 29°C / 25°C | 35°C / 30°C | 28days (304 mm) Wet | 8.6h Good | 88% Very Muggy | 7.5 Very High | Wet | View Details |
| August | 29°C / 25°C | 35°C / 30°C | 28days (252 mm) Wet | 9.3h Good | 88% Very Muggy | 8.2 Very High | Wet | View Details |
| September | 29°C / 25°C | 35°C / 30°C | 26days (292 mm) Wet | 8.8h Good | 87% Very Muggy | 8.4 Very High | Wet | View Details |
| October | 29°C / 25°C | 36°C / 30°C | 29days (293 mm) Wet | 8.5h Good | 87% Very Muggy | 8.3 Very High | Wet | View Details |
| November | 30°C / 25°C | 36°C / 30°C | 26days (214 mm) Wet | 9.5h Good | 86% Very Muggy | 7.6 Very High | Wet | View Details |
| December | 30°C / 25°C | 36°C / 30°C | 24days (180 mm) Wet | 9.4h Good | 85% Humid | 7.2 Very High | Wet | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Siay are February, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Siay, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Siay is March, 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 Siay is January, with average overnight lows of 25°C (77°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Siay is June, averaging 318mm of precipitation across 28 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Siay runs through October, May, June, July, with the heaviest rainfall in October. Based on 10-year averages for Siay.
Siay receives approximately 112 sunshine hours per year. The sunniest month is March with around 11 hours. Based on climate data for Siay.
The least favorable months to visit Siay are April, May, September, October, primarily due to extreme heat, heavy rainfall, oppressive humidity. For the best conditions, consider February instead.
The annual average UV index in Siay is 8, classified as high. SPF 30+ sunscreen, sunglasses, and seeking shade between 10:00–16:00 are strongly recommended.
Average humidity in Siay is 85%, 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 30°C (86°F), which is warm and comfortable for swimming and water activities.
Average wind speeds in Siay are 12 km/h (7 mph). The windiest month is July with peak winds reaching 13 km/h (8 mph) (gusts up to 28 km/h / 18 mph).
Siay averages 0 clear-sky days per month with overall cloud cover around 81%. The clearest skies occur in February.
The annual average dew point in Siay is 24°C (75°F), which feels oppressively humid. Expect heavy perspiration during warmer months — stay hydrated and take breaks in air-conditioned spaces.
Siay 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 Siay 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 Siay, with a climate score of 2.1/10. Consider visiting during February instead for better conditions.
For June in Siay, pack Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). With average highs of 29°C (84°F) and 28 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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