★ January30° · ☂ 18 ★ February30° · ☂ 13 March 31° · ☂ 15 April 31° · ☂ 16 May 32° · ☂ 17 June 31° · ☂ 19 July 31° · ☂ 22 August 31° · ☂ 23 September 31° · ☂ 24 October 31° · ☂ 24 November 31° · ☂ 20 ★ December30° · ☂ 19 Guam in January:hot, rain on every second day Guam · Records from 2006 to 2025. Not a forecast.
Mean high 30° Hottest day 31.2° (2025)
Mean low 24° Coldest night 22.6° (2016)
Rain days 18 days 11-26 by year
Rainfall 163mm Daylight 11.3 → 11.5 h
Guam's 12 months i Best: December to February
1 2 3 4 5 6 7 8 9 10 11 12
Trip types Beach Poorfrequent rain Sightseeing on foot Poorfrequent rain and muggy
Humidity 80% 30 muggy days
Clear days 5 days 6 overcast days
Mean wind 30 km/h 17 windy days
Sea temperature 28.6° 28.5-28.8° by year (last 6)
Sunrise / sunset (15th) 06:47 / 18:12 Daylight 11.3 → 11.5 h
Guam in January The dry season has begun, though there are still a fair number of rainy days. Showers pass quickly and rarely wreck the whole schedule. A good time to swap a cold winter for warm water.
January brought serious heat to Guam, 30°C on a typical afternoon and 24°C overnight. Early mornings were the best time to be outside. Rain was a regular part of the month, showing up on 18 days on average. It varied a lot from year to year. January 2021 had 11 rain days; 2017 had 26.
With 13 days above 30°C on average, most of the month felt like high summer.
Typhoons i Typhoons: February to December
Date by date i Sun
Mon
Tue
Wed
Thu
Fri
Sat
Week
January 1 Friday 1 rain in 12 of 20 yrs 12/20 30° 24° January 2 Saturday 2 rain in 11 of 20 yrs 11/20 30° 24° 1-2 rain on 58% of days 30° 24°
January 3 Sunday 3 rain in 11 of 20 yrs 11/20 30° 24° January 4 Monday 4 rain in 13 of 20 yrs 13/20 30° 24° January 5 Tuesday 5 rain in 12 of 20 yrs 12/20 30° 24° January 6 Wednesday 6 rain in 12 of 20 yrs 12/20 30° 24° January 7 Thursday 7 rain in 13 of 20 yrs 13/20 30° 24° January 8 Friday 8 rain in 13 of 20 yrs 13/20 30° 24° January 9 Saturday 9 rain in 13 of 20 yrs 13/20 30° 24° 3-9 rain on 62% of days 30° 24°
January 10 Sunday 10 rain in 13 of 20 yrs 13/20 30° 24° January 11 Monday 11 rain in 13 of 20 yrs 13/20 30° 24° January 12 Tuesday 12 rain in 13 of 20 yrs 13/20 30° 24° January 13 Wednesday 13 rain in 12 of 20 yrs 12/20 30° 24° January 14 Thursday 14 rain in 12 of 20 yrs 12/20 30° 24° January 15 Friday 15 rain in 14 of 20 yrs 14/20 30° 24° January 16 Saturday 16 rain in 13 of 20 yrs 13/20 30° 24° 10-16 rain on 64% of days 30° 24°
January 17 Sunday 17 rain in 12 of 20 yrs 12/20 30° 24° January 18 Monday 18 rain in 7 of 20 yrs 7/20 30° 24° January 19 Tuesday 19 rain in 12 of 20 yrs 12/20 30° 24° January 20 Wednesday 20 rain in 10 of 20 yrs 10/20 30° 24° January 21 Thursday 21 rain in 12 of 20 yrs 12/20 30° 24° January 22 Friday 22 rain in 14 of 20 yrs 14/20 30° 24° January 23 Saturday 23 rain in 10 of 20 yrs 10/20 30° 24° 17-23 rain on 55% of days 30° 24°
January 24 Sunday 24 rain in 8 of 20 yrs 8/20 30° 24° January 25 Monday 25 rain in 7 of 20 yrs 7/20 30° 24° January 26 Tuesday 26 rain in 14 of 20 yrs 14/20 30° 24° January 27 Wednesday 27 rain in 15 of 20 yrs 15/20 29° 24° January 28 Thursday 28 rain in 13 of 20 yrs 13/20 30° 24° January 29 Friday 29 rain in 12 of 20 yrs 12/20 30° 24° January 30 Saturday 30 rain in 11 of 20 yrs 11/20 30° 24° 24-30 rain on 57% of days 30° 24°
January 31 Sunday 31 rain in 8 of 20 yrs 8/20 30° 24°
January 31 rain on 40% of days 30° 24°
Rain was common on almost every date this month, so the shades compare dates within this month.
1-2 rain on 58% of days 30° 24° 3-9 rain on 62% of days 30° 24° 10-16 rain on 64% of days 30° 24° 17-23 rain on 55% of days 30° 24° 24-30 rain on 57% of days 30° 24° January 31 rain on 40% of days 30° 24°
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Week
January 1 Saturday 1 rain in 12 of 20 yrs 12/20 30° 24° January 1 rain on 60% of days 30° 24°
January 2 Sunday 2 rain in 11 of 20 yrs 11/20 30° 24° January 3 Monday 3 rain in 11 of 20 yrs 11/20 30° 24° January 4 Tuesday 4 rain in 13 of 20 yrs 13/20 30° 24° January 5 Wednesday 5 rain in 12 of 20 yrs 12/20 30° 24° January 6 Thursday 6 rain in 12 of 20 yrs 12/20 30° 24° January 7 Friday 7 rain in 13 of 20 yrs 13/20 30° 24° January 8 Saturday 8 rain in 13 of 20 yrs 13/20 30° 24° 2-8 rain on 61% of days 30° 24°
January 9 Sunday 9 rain in 13 of 20 yrs 13/20 30° 24° January 10 Monday 10 rain in 13 of 20 yrs 13/20 30° 24° January 11 Tuesday 11 rain in 13 of 20 yrs 13/20 30° 24° January 12 Wednesday 12 rain in 13 of 20 yrs 13/20 30° 24° January 13 Thursday 13 rain in 12 of 20 yrs 12/20 30° 24° January 14 Friday 14 rain in 12 of 20 yrs 12/20 30° 24° January 15 Saturday 15 rain in 14 of 20 yrs 14/20 30° 24° 9-15 rain on 64% of days 30° 24°
January 16 Sunday 16 rain in 13 of 20 yrs 13/20 30° 24° January 17 Monday 17 rain in 12 of 20 yrs 12/20 30° 24° January 18 Tuesday 18 rain in 7 of 20 yrs 7/20 30° 24° January 19 Wednesday 19 rain in 12 of 20 yrs 12/20 30° 24° January 20 Thursday 20 rain in 10 of 20 yrs 10/20 30° 24° January 21 Friday 21 rain in 12 of 20 yrs 12/20 30° 24° January 22 Saturday 22 rain in 14 of 20 yrs 14/20 30° 24° 16-22 rain on 57% of days 30° 24°
January 23 Sunday 23 rain in 10 of 20 yrs 10/20 30° 24° January 24 Monday 24 rain in 8 of 20 yrs 8/20 30° 24° January 25 Tuesday 25 rain in 7 of 20 yrs 7/20 30° 24° January 26 Wednesday 26 rain in 14 of 20 yrs 14/20 30° 24° January 27 Thursday 27 rain in 15 of 20 yrs 15/20 29° 24° January 28 Friday 28 rain in 13 of 20 yrs 13/20 30° 24° January 29 Saturday 29 rain in 12 of 20 yrs 12/20 30° 24° 23-29 rain on 56% of days 30° 24°
January 30 Sunday 30 rain in 11 of 20 yrs 11/20 30° 24° January 31 Monday 31 rain in 8 of 20 yrs 8/20 30° 24°
30-31 rain on 48% of days 30° 24°
Rain was common on almost every date this month, so the shades compare dates within this month.
January 1 rain on 60% of days 30° 24° 2-8 rain on 61% of days 30° 24° 9-15 rain on 64% of days 30° 24° 16-22 rain on 57% of days 30° 24° 23-29 rain on 56% of days 30° 24° 30-31 rain on 48% of days 30° 24°
Tap another date to change
2006 none
2007 3mm
2008 none
2009 1mm
2010 2mm
2011 10mm
2012 1mm
2013 none
2014 171mm
2015 1mm
2016 none
2017 3mm
2018 3mm
2019 20mm
2020 1mm
2021 3mm
2022 1mm
2023 none
2024 6mm
2025 5mm
Holidays in January (2027) January 1 New Year's DayJanuary 18 Martin Luther King, Jr. DayJanuary 18 Birthday of Martin Luther King, Jr. 1 Local public holiday or break (busier, pricier)1 US holidays (flights fill up)
Your trip dates, the past 20 years Trip dates January 1 (Fri) 2 (Sat) 3 (Sun) 4 (Mon) 5 (Tue) 6 (Wed) 7 (Thu) 8 (Fri) 9 (Sat) 10 (Sun) 11 (Mon) 12 (Tue) 13 (Wed) 14 (Thu) 15 (Fri) 16 (Sat) 17 (Sun) 18 (Mon) 19 (Tue) 20 (Wed) 21 (Thu) 22 (Fri) 23 (Sat) 24 (Sun) 25 (Mon) 26 (Tue) 27 (Wed) 28 (Thu) 29 (Fri) 30 (Sat) 31 (Sun) ~ January 1 (Fri) 2 (Sat) 3 (Sun) 4 (Mon) 5 (Tue) 6 (Wed) 7 (Thu) 8 (Fri) 9 (Sat) 10 (Sun) 11 (Mon) 12 (Tue) 13 (Wed) 14 (Thu) 15 (Fri) 16 (Sat) 17 (Sun) 18 (Mon) 19 (Tue) 20 (Wed) 21 (Thu) 22 (Fri) 23 (Sat) 24 (Sun) 25 (Mon) 26 (Tue) 27 (Wed) 28 (Thu) 29 (Fri) 30 (Sat) 31 (Sun) 1-7 8-14 15-21 22-end Whole month
You can also click two dates on the axis. Hover a cell to see that day's rain. By year Driest trips first
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Trip rain days Month rain days Tap a date to start, tap another to end. Each cell is that date in one year. '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16 '17 '18 '19 '20 '21 '22 '23 '24 '25
of 20 10 Sun Pick January 10
13 11 Mon Pick January 11
13 12 Tue Pick January 12
13 13 Wed Pick January 13
12 14 Thu Pick January 14
12 15 Fri Pick January 15
14 16 Sat Pick January 16
13 17 Sun Pick January 17
12 19 Tue Pick January 19
12 20 Wed Pick January 20
10 21 Thu Pick January 21
12 22 Fri Pick January 22
14 23 Sat Pick January 23
10 26 Tue Pick January 26
14 27 Wed Pick January 27
15 28 Thu Pick January 28
13 29 Fri Pick January 29
12 30 Sat Pick January 30
11 Dates outside your trip are dimmed.
One row per year, one cell per day. 2021 had 11 rain days, 2017 had 26.
Guam through the year Month High Low Rain days Rainfall Sea January Good 30° 24° 18 days 163mm 29° February Good 30° 24° 13 days 100mm 28° March 31° 24° 15 days 91mm 28° April 31° 25° 16 days 104mm 29° May 32° 25° 17 days 139mm 29° June 31° 25° 19 days 155mm 30° July 31° 25° 22 days 314mm 30° August 31° 25° 23 days 451mm 30° September 31° 25° 24 days 444mm 30° October 31° 25° 24 days 427mm 30° November 31° 25° 20 days 186mm 30° December Good 30° 25° 19 days 121mm 29°
What to pack Loose linen or quick-dry cotton, a wide-brimmed hat and sunscreen were the basics. A water bottle stayed in the bag, and midday plans moved indoors.
With rain every other day, a waterproof jacket is a necessity, not extra luggage. One compact umbrella is enough besides.
Common questions Does it rain a lot in Guam in January? Over the past 20 years January averaged 18 rain days (1 mm or more) out of 31. Individual years ran from 11 in the driest to 26 in the wettest.
What should I wear in Guam in January? Days averaged 30°C and nights 24°C. Pack an umbrella, sandals that can get wet, T-shirts, sunscreen plus a hat, a swimsuit, and insect repellent.
Can you swim in Guam in January? Sea surface temperature averaged 28.6°C in January, warm enough to stay in for a long swim. Year to year it ranged 28.5-28.8°C. Check local flags for waves and jellyfish on the day.
Is January a good time to visit Guam? On warmth and rain days alone, Guam's easiest months were December to February. January ranked 2 of 12, close to the top.
Is Guam humid in January? Mean relative humidity was 80%, with about 30 muggy days (dew point of 20°C or more) in the month.
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