Last updated: June 24, 2025
In December, the average temperature in Lisbon, United States hovers around -2°C (29°F). Expect chilly conditions with a minimum plunge to -23°C (-9°F) and a maximum reach of 15°C (59°F). Precipitation typically totals 120 mm (4.7 in) over about 10 days, contributing to an average humidity level of 81%. Be prepared for a crisp and damp atmosphere!
In December in Lisbon, the average temperature is -2°C (29°F), with maximums reaching up to 15°C (59°F) and minimums dropping as low as -23°C (-9°F). Be prepared for a range of temperatures when traveling to Lisbon during this time, ensuring you pack both warm and mild weather clothing.
In Lisbon in December, the precipitation amount is 120 mm (4.7 in) spread over a duration of 10 days.
In Lisbon in December humidity is 81%. With an average temperature of -2°C (29°F), this humidity feels like an uncomfortable chill that seeps into your bones, making outdoor activities less enjoyable and requiring extra layers to stay warm while traveling.
In Lisbon in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Lisbon, you can visit Hourly UV Index in Lisbon.
UV Risk Categories
Weather in Lisbon varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Lisbon, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (25°F) | 83 mm (3.3 inches) | 86% | low |
| February Weather | -3°C (27°F) | 87 mm (3.4 inches) | 84% | moderate |
| March Weather | 0°C (33°F) | 73 mm (2.9 inches) | 82% | moderate |
| April Weather | 7°C (44°F) | 118 mm (4.7 inches) | 80% | high |
| May Weather | 12°C (55°F) | 78 mm (3.1 inches) | 72% | very high |
| June Weather | 18°C (65°F) | 66 mm (2.6 inches) | 72% | very high |
| July Weather | 21°C (70°F) | 117 mm (4.6 inches) | 67% | very high |
| August Weather | 21°C (70°F) | 77 mm (3.0 inches) | 66% | very high |
| September Weather | 17°C (63°F) | 70 mm (2.8 inches) | 71% | high |
| October Weather | 11°C (53°F) | 131 mm (5.1 inches) | 78% | moderate |
| November Weather | 4°C (39°F) | 114 mm (4.5 inches) | 84% | moderate |
| December Weather | -2°C (29°F) | 120 mm (4.7 inches) | 81% | low |