Port Arthur weather in December
In December, Port Arthur sees average daytime highs of 63°F and overnight lows near 48°F, with 4.7 in of precipitation across 9.5 wet days and about 10.1 hours of daylight. It is the 11th-warmest and 4th-wettest month of the year here.
Highs ease over the month, from about 65°F in the first days to 61°F by the end. The sky is clear or mostly clear about 33% of the time in December, and the air most often feels dry.
Daylight stretches from about 10 h 12 min at the start of December to 10 h 06 min by month's end. Set against the rest of the year, December is Port Arthur's 11th-clearest and 5th-windiest month. For the whole year in context, see Port Arthur's year-round climate.
- Daytime high
- 63°
- 11th warmest
- Overnight low
- 48°
- 2nd coldest
- Precipitation
- 4.7 in
- 9.5 wet days
- Daylight
- 10 h 06 min
- 7:09 AM – 5:15 PM
- Cloud cover
- 59%
- 11th clearest
- Wind
- 8 mph
- 5th windiest
- Solar energy
- 2.67 kWh/m²
- Travel score
- 5.6
- out of 10
Port Arthur is city in Jefferson County, Texas, United States.
- Density
- 148/km²
- people per km²
- Founded
- 1895
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in December
Highs ease over the month, from about 65°F in the first days to 61°F by the end.
A typical December day in Port Arthur reaches about 63°F in the afternoon and slips back to 48°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 51°F and 74°F. Set against its neighbours, December runs about 7°F cooler than November and about 2°F warmer than January.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 66 | 66 | 65 | 65 | 65 | 65 | 64 | 64 | 64 | 64 | 64 | 64 | 63 | 63 | 63 | 63 | 63 | 63 | 62 | 62 | 62 | 62 | 62 | 62 | 62 | 61 | 61 | 61 | 61 | 61 | 61 |
| Avg low (°F) | 50 | 50 | 50 | 49 | 49 | 49 | 49 | 49 | 49 | 48 | 48 | 48 | 48 | 48 | 48 | 48 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 46 | 46 | 46 | 46 | 46 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 66 | 50 |
| 2 | 66 | 50 |
| 3 | 65 | 50 |
| 4 | 65 | 49 |
| 5 | 65 | 49 |
| 6 | 65 | 49 |
| 7 | 64 | 49 |
| 8 | 64 | 49 |
| 9 | 64 | 49 |
| 10 | 64 | 48 |
| 11 | 64 | 48 |
| 12 | 64 | 48 |
| 13 | 63 | 48 |
| 14 | 63 | 48 |
| 15 | 63 | 48 |
| 16 | 63 | 48 |
| 17 | 63 | 47 |
| 18 | 63 | 47 |
| 19 | 62 | 47 |
| 20 | 62 | 47 |
| 21 | 62 | 47 |
| 22 | 62 | 47 |
| 23 | 62 | 47 |
| 24 | 62 | 47 |
| 25 | 62 | 47 |
| 26 | 61 | 47 |
| 27 | 61 | 46 |
| 28 | 61 | 46 |
| 29 | 61 | 46 |
| 30 | 61 | 46 |
| 31 | 61 | 46 |
How December really feels in Port Arthur
Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Port Arthur weather by month
How December compares with the rest of the year at a glance. December is the 11th-warmest and 4th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 61° / 46° | 4.7 | 9.8 | 10.3 | 5.1 |
| Feb | 64° / 49° | 3.4 | 8.7 | 10.9 | 5.9 |
| Mar | 70° / 56° | 3.9 | 9.5 | 11.8 | 6.6 |
| Apr | 76° / 62° | 4.4 | 9.4 | 12.7 | 7.0 |
| May | 83° / 69° | 3.8 | 10.7 | 13.5 | 6.0 |
| Jun | 87° / 75° | 5.2 | 15.1 | 13.9 | 4.2 |
| Jul | 89° / 77° | 4.2 | 15.9 | 13.7 | 3.6 |
| Aug | 89° / 76° | 4.8 | 15.7 | 13.1 | 3.6 |
| Sep | 86° / 72° | 5.4 | 12.3 | 12.2 | 4.8 |
| Oct | 79° / 63° | 4.1 | 8.8 | 11.3 | 7.1 |
| Nov | 70° / 53° | 4.3 | 8.6 | 10.5 | 6.8 |
| Dec | 63° / 48° | 4.7 | 9.5 | 10.1 | 5.6 |
Cloud cover in December
The sky is clear or mostly clear about 33% of the time in December.
Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 54%.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 51 | 50 | 50 | 48 | 48 | 48 | 48 | 47 | 46 | 46 | 46 | 46 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 46 | 44 | 44 | 44 | 43 | 43 | 43 | 43 | 43 |
| Cloudier (%) | 49 | 50 | 50 | 52 | 52 | 52 | 52 | 53 | 54 | 54 | 54 | 54 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 54 | 56 | 56 | 56 | 57 | 57 | 57 | 57 | 57 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 51 | 49 |
| 2 | 50 | 50 |
| 3 | 50 | 50 |
| 4 | 48 | 52 |
| 5 | 48 | 52 |
| 6 | 48 | 52 |
| 7 | 48 | 52 |
| 8 | 47 | 53 |
| 9 | 46 | 54 |
| 10 | 46 | 54 |
| 11 | 46 | 54 |
| 12 | 46 | 54 |
| 13 | 47 | 53 |
| 14 | 47 | 53 |
| 15 | 47 | 53 |
| 16 | 47 | 53 |
| 17 | 47 | 53 |
| 18 | 47 | 53 |
| 19 | 47 | 53 |
| 20 | 47 | 53 |
| 21 | 47 | 53 |
| 22 | 47 | 53 |
| 23 | 46 | 54 |
| 24 | 44 | 56 |
| 25 | 44 | 56 |
| 26 | 44 | 56 |
| 27 | 43 | 57 |
| 28 | 43 | 57 |
| 29 | 43 | 57 |
| 30 | 43 | 57 |
| 31 | 43 | 57 |
Chance of precipitation in December
Port Arthur gets around 4.7 in of rain and snow over 9.5 wet days in December. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable precipitation averages around 31% and peaks near 33% on the wettest days, and about 0 day brings snow.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 29 | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 30 | 31 | 31 | 31 | 31 | 32 | 32 | 32 | 32 | 33 | 33 | 32 | 32 | 32 | 32 | 32 | 31 | 31 | 30 | 30 | 30 | 30 | 30 |
| Rain chance (%) | |
|---|---|
| 1 | 29 |
| 2 | 29 |
| 3 | 29 |
| 4 | 29 |
| 5 | 29 |
| 6 | 30 |
| 7 | 30 |
| 8 | 30 |
| 9 | 30 |
| 10 | 31 |
| 11 | 31 |
| 12 | 31 |
| 13 | 31 |
| 14 | 32 |
| 15 | 32 |
| 16 | 32 |
| 17 | 32 |
| 18 | 33 |
| 19 | 33 |
| 20 | 32 |
| 21 | 32 |
| 22 | 32 |
| 23 | 32 |
| 24 | 32 |
| 25 | 31 |
| 26 | 31 |
| 27 | 30 |
| 28 | 30 |
| 29 | 30 |
| 30 | 30 |
| 31 | 30 |
Humidity in December
Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, December lands in the dry band about 69% of days. Sticky, muggy-or-worse air turns up on roughly 9% of them.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 63 | 63 | 64 | 64 | 64 | 64 | 65 | 65 | 65 | 67 | 67 | 67 | 68 | 68 | 69 | 69 | 70 | 70 | 71 | 72 | 72 | 73 | 73 | 73 | 74 | 74 | 75 | 75 | 76 | 75 | 75 |
| Comfortable (%) | 12 | 12 | 12 | 12 | 12 | 12 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 12 | 12 | 12 | 11 | 11 | 10 | 10 | 10 | 9 | 9 | 9 | 9 | 8 | 9 | 9 |
| Humid (%) | 12 | 12 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 |
| Muggy (%) | 12 | 12 | 12 | 12 | 12 | 12 | 11 | 11 | 11 | 10 | 10 | 10 | 9 | 9 | 8 | 8 | 8 | 8 | 7 | 7 | 7 | 6 | 6 | 6 | 6 | 6 | 5 | 5 | 5 | 5 | 5 |
| Oppressive (%) | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|---|
| 1 | 63 | 12 | 12 | 12 | 1 |
| 2 | 63 | 12 | 12 | 12 | 1 |
| 3 | 64 | 12 | 11 | 12 | 1 |
| 4 | 64 | 12 | 11 | 12 | 1 |
| 5 | 64 | 12 | 11 | 12 | 1 |
| 6 | 64 | 12 | 11 | 12 | 1 |
| 7 | 65 | 13 | 11 | 11 | 0 |
| 8 | 65 | 13 | 11 | 11 | 0 |
| 9 | 65 | 13 | 11 | 11 | 0 |
| 10 | 67 | 13 | 10 | 10 | 0 |
| 11 | 67 | 13 | 10 | 10 | 0 |
| 12 | 67 | 13 | 10 | 10 | 0 |
| 13 | 68 | 13 | 10 | 9 | 0 |
| 14 | 68 | 13 | 10 | 9 | 0 |
| 15 | 69 | 13 | 10 | 8 | 0 |
| 16 | 69 | 13 | 10 | 8 | 0 |
| 17 | 70 | 12 | 10 | 8 | 0 |
| 18 | 70 | 12 | 10 | 8 | 0 |
| 19 | 71 | 12 | 10 | 7 | 0 |
| 20 | 72 | 11 | 10 | 7 | 0 |
| 21 | 72 | 11 | 10 | 7 | 0 |
| 22 | 73 | 10 | 11 | 6 | 0 |
| 23 | 73 | 10 | 11 | 6 | 0 |
| 24 | 73 | 10 | 11 | 6 | 0 |
| 25 | 74 | 9 | 11 | 6 | 0 |
| 26 | 74 | 9 | 11 | 6 | 0 |
| 27 | 75 | 9 | 11 | 5 | 0 |
| 28 | 75 | 9 | 11 | 5 | 0 |
| 29 | 76 | 8 | 11 | 5 | 0 |
| 30 | 75 | 9 | 11 | 5 | 0 |
| 31 | 75 | 9 | 11 | 5 | 0 |
Wind in December
Winds average 8 mph in December.
Across December, daily wind ranges from about 8 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 8 | light breeze |
| 2 | 8 | light breeze |
| 3 | 8 | light breeze |
| 4 | 8 | light breeze |
| 5 | 8 | light breeze |
| 6 | 8 | light breeze |
| 7 | 8 | light breeze |
| 8 | 8 | light breeze |
| 9 | 8 | light breeze |
| 10 | 8 | light breeze |
| 11 | 8 | light breeze |
| 12 | 8 | light breeze |
| 13 | 8 | light breeze |
| 14 | 8 | light breeze |
| 15 | 8 | light breeze |
| 16 | 8 | light breeze |
| 17 | 9 | light breeze |
| 18 | 9 | light breeze |
| 19 | 8 | light breeze |
| 20 | 8 | light breeze |
| 21 | 8 | light breeze |
| 22 | 8 | light breeze |
| 23 | 8 | light breeze |
| 24 | 8 | light breeze |
| 25 | 8 | light breeze |
| 26 | 8 | light breeze |
| 27 | 8 | light breeze |
| 28 | 8 | light breeze |
| 29 | 8 | light breeze |
| 30 | 8 | light breeze |
| 31 | 8 | light breeze |
Sunrise & sunset in December
Daylight runs from about 10 h 12 min at the start of December to 10 h 06 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 6 minutes over December. Sunrise moves from 6:59 AM to 7:16 AM, and sunset from 5:12 PM to 5:22 PM.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 10.2 | 10.2 | 10.2 | 10.2 | 10.2 | 10.2 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 | 10.1 |
| Sunrise (AM) | 6:59 | 7:00 | 7:01 | 7:01 | 7:02 | 7:03 | 7:03 | 7:04 | 7:05 | 7:06 | 7:06 | 7:07 | 7:07 | 7:08 | 7:09 | 7:09 | 7:10 | 7:10 | 7:11 | 7:11 | 7:12 | 7:12 | 7:13 | 7:13 | 7:14 | 7:14 | 7:15 | 7:15 | 7:15 | 7:16 | 7:16 |
| Sunset (PM) | 5:12 | 5:12 | 5:12 | 5:12 | 5:12 | 5:12 | 5:12 | 5:13 | 5:13 | 5:13 | 5:13 | 5:13 | 5:14 | 5:14 | 5:14 | 5:15 | 5:15 | 5:15 | 5:16 | 5:16 | 5:17 | 5:17 | 5:18 | 5:18 | 5:19 | 5:19 | 5:20 | 5:20 | 5:21 | 5:21 | 5:22 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 10.2 | 6:59 | 5:12 |
| 2 | 10.2 | 7:00 | 5:12 |
| 3 | 10.2 | 7:01 | 5:12 |
| 4 | 10.2 | 7:01 | 5:12 |
| 5 | 10.2 | 7:02 | 5:12 |
| 6 | 10.2 | 7:03 | 5:12 |
| 7 | 10.1 | 7:03 | 5:12 |
| 8 | 10.1 | 7:04 | 5:13 |
| 9 | 10.1 | 7:05 | 5:13 |
| 10 | 10.1 | 7:06 | 5:13 |
| 11 | 10.1 | 7:06 | 5:13 |
| 12 | 10.1 | 7:07 | 5:13 |
| 13 | 10.1 | 7:07 | 5:14 |
| 14 | 10.1 | 7:08 | 5:14 |
| 15 | 10.1 | 7:09 | 5:14 |
| 16 | 10.1 | 7:09 | 5:15 |
| 17 | 10.1 | 7:10 | 5:15 |
| 18 | 10.1 | 7:10 | 5:15 |
| 19 | 10.1 | 7:11 | 5:16 |
| 20 | 10.1 | 7:11 | 5:16 |
| 21 | 10.1 | 7:12 | 5:17 |
| 22 | 10.1 | 7:12 | 5:17 |
| 23 | 10.1 | 7:13 | 5:18 |
| 24 | 10.1 | 7:13 | 5:18 |
| 25 | 10.1 | 7:14 | 5:19 |
| 26 | 10.1 | 7:14 | 5:19 |
| 27 | 10.1 | 7:15 | 5:20 |
| 28 | 10.1 | 7:15 | 5:20 |
| 29 | 10.1 | 7:15 | 5:21 |
| 30 | 10.1 | 7:16 | 5:21 |
| 31 | 10.1 | 7:16 | 5:22 |
Solar energy in December
Average shortwave solar energy reaching the ground each day in December, about 2.67 kWh/m² — the year's lowest.
For context, solar energy here swings from a low near 2.67 kWh/m² to a high of 6.21 kWh/m² in July across the year — December's 2.67 kWh/m² sits near the bottom.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 2.9 | 2.9 | 2.8 | 2.8 | 2.8 | 2.8 | 2.7 | 2.7 | 2.7 | 2.7 | 2.7 | 2.7 | 2.7 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.7 | 2.7 | 2.7 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 2.9 | Moderate |
| 2 | 2.9 | Moderate |
| 3 | 2.8 | Moderate |
| 4 | 2.8 | Moderate |
| 5 | 2.8 | Moderate |
| 6 | 2.8 | Moderate |
| 7 | 2.7 | Moderate |
| 8 | 2.7 | Moderate |
| 9 | 2.7 | Moderate |
| 10 | 2.7 | Moderate |
| 11 | 2.7 | Moderate |
| 12 | 2.7 | Moderate |
| 13 | 2.7 | Moderate |
| 14 | 2.6 | Moderate |
| 15 | 2.6 | Moderate |
| 16 | 2.6 | Moderate |
| 17 | 2.6 | Moderate |
| 18 | 2.6 | Moderate |
| 19 | 2.6 | Moderate |
| 20 | 2.6 | Moderate |
| 21 | 2.6 | Moderate |
| 22 | 2.6 | Moderate |
| 23 | 2.6 | Moderate |
| 24 | 2.6 | Moderate |
| 25 | 2.6 | Moderate |
| 26 | 2.6 | Moderate |
| 27 | 2.6 | Moderate |
| 28 | 2.6 | Moderate |
| 29 | 2.7 | Moderate |
| 30 | 2.7 | Moderate |
| 31 | 2.7 | Moderate |
Hazard calendar for Port Arthur
None of Port Arthur's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
Port Arthur sits in the Atlantic hurricane belt; the season peaks August–October.
Is December a good time to visit Port Arthur?
Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
December is a reasonable time to visit Port Arthur for sightseeing.
What to pack for Port Arthur in December
From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In December, Port Arthur sees daytime highs around 63°F and nights near 48°F. Worth packing: rain gear. About 10 days see rain.
Sea temperature near Port Arthur in December
The nearest coast averages about 62°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 19 mi away) is warmest in August at about 86°F and coldest in January near 58°F.
It's comfortable for a long swim from Apr 3 to Nov 19 — about 7.6 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 58 | 59 | 64 | 71 | 78 | 84 | 86 | 86 | 84 | 77 | 69 | 62 |
| Comfort | Bracing | Cool | Cool | Refreshing | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Refreshing | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 58 | Bracing |
| Feb | 59 | Cool |
| Mar | 64 | Cool |
| Apr | 71 | Refreshing |
| May | 78 | Warm |
| Jun | 84 | Tropical |
| Jul | 86 | Tropical |
| Aug | 86 | Tropical |
| Sep | 84 | Tropical |
| Oct | 77 | Warm |
| Nov | 69 | Refreshing |
| Dec | 62 | Cool |
UV index in Port Arthur in December
Clear-sky midday UV in December peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Port Arthur peaks around July 14 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 4 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 4 | 6 | 7 | 10 | 10 | 10 | 10 | 10 | 8 | 6 | 5 | 4 |
| Level | Moderate | High | High | Very high | Extreme | Extreme | Extreme | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 6 | High |
| Mar | 7 | High |
| Apr | 10 | Very high |
| May | 10 | Extreme |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 10 | Extreme |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 5 | Moderate |
| Dec | 4 | Moderate |
Air quality in Port Arthur in December
Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.
Air quality in Port Arthur is worst in July — around 22 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (December, 8 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 10 | 11 | 12 | 11 | 13 | 18 | 22 | 17 | 14 | 11 | 9 | 8 |
| Level | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 10 | Good |
| Feb | 11 | Good |
| Mar | 12 | Good |
| Apr | 11 | Good |
| May | 13 | Moderate |
| Jun | 18 | Moderate |
| Jul | 22 | Moderate |
| Aug | 17 | Moderate |
| Sep | 14 | Moderate |
| Oct | 11 | Good |
| Nov | 9 | Good |
| Dec | 8 | Good |
Where is Port Arthur?
Port Arthur sits at 29.9°N, 93.9°W, 7 ft above sea level, in United States. The nearest listed city is Groves, 4.3 mi away.
Topography around Port Arthur
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Port Arthur.
Within 2 miles, the terrain around Port Arthur has only modest variations in elevation — a maximum elevation change of 56 ft around an average of 7 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 75 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 190 ft.
The land around Port Arthur is covered by artificial surfaces (28%), grassland (24%) and trees (22%) within 2 miles, water (36%) and wetland (30%) within 10 miles, and trees (35%) and water (32%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Port Arthur (29.8852°, -93.9423°, elevation 7 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).