Is Los Angeles humid? LA is known for its vibrant entertainment industry, diverse cultural attractions, and beautifully sunny weather.
However, those who are currently thinking of relocating to LA often ask questions about its humidity levels.
The truth is that generally, the humidity is on the lower side, but seasonal variations can be quite intense.
Also, regional microclimates are capable of causing fluctuations in humidity, which makes people ask, “Why is it humid in Los Angeles?”
LA experiences occasional humidity mainly due to coastal proximity, seasonal variations, and microclimates, but overall, it has moderate humidity.
Is Los Angeles Humid?
Los Angeles has moderate humidity, though the levels are constantly going up.
Los Angeles has a subtropical climate similar to the Mediterranean coasts but being at a lower latitude is slightly warmer and milder.
Yearly temperatures are typically in the range of 480F to 850F with rare extremes of no lower than 42°F or above 93°F.
Summers are warm and dry with clear blue skies and the winters long, cool and occasionally cloudy.
Overall, the LA climate is comfortable with plenty of sunshine and bad weather when it comes, arrives in waves from December through March.
It can be windy anytime but in winter the wind can lift the temperature.
General Humidity Levels in Los Angeles
LA is one of the fastest heating cities with temperatures around 4% higher than in the 19th century.
Like other warming cities, LA experiences the urban heat effect.
It used to have a much drier climate but there is more moisture in the air now and it gets humid.
Fact: The terrain of Los Angeles is so diverse that different parts of the city experience vastly varying temperatures, even at relatively close proximity.
LA Compared to Other Cities
Los Angeles enjoys weather conditions that are different from other American cities with cool summers and warm winters.
In summer, inland temperatures can be hotter than those in New York City but humidity is lower.
Unlike New York, LA traditionally experiences cooler temperatures at night although this seems to be changing.
Whereas the southern cities are both hot and humid in summer, the summer season in LA stays dry due to the cooling effects of the ocean.
Although Houston is also sub-tropical it is considerably more humid at 90% dropping to 60% through the day as afternoon showers and thunderstorms develop.
Seasonal Fluctuations in Temperature and Humidity
When in LA, you will quickly notice seasonal fluctuations in temperature and humidity, which are rather pronounced in certain regions.
In general, LA has two seasons:
- The warm from July, with temperatures peaking in the mid-eighties by August.
- The cold season runs from the end of November to the third week in March.
Since night-time temperatures are higher too, uncomfortable summers are increasing.
It is worth mentioning that rising temperatures contribute to rising humidity.
Warm air holds more water than cold and the Pacific Ocean coastal LA sits on is warming.
There is a lot more moisture in the atmosphere generally. May is the most humid at 73.0%. November is the least at 50.0%.
Fact: The urban heat island effect causes temperatures and humidity to rise in Los Angeles and other large cities because of the absorption and re-radiation of heat by urban surfaces.
Factors Affecting Humidity in Los Angeles
So, is it humid in Los Angeles? Traditionally, LA has low humidity levels, but it is certainly changing.
And a number of factors make LA a fast-warming city.
It is a vast settlement on a long coastal plain with low mountains and valleys behind it.
As a city, it is an asphalt heat island soaking in heat from sunshine driving evaporation until the water vapor fills the air with moisture.
Here are some reasons why LA is fast becoming a more humid city:
Proximity to the Pacific Ocean
Los Angeles’ climate is moderated by its proximity to the Pacific Ocean.
Although because of the winds, it experiences a variety of weather conditions that are relative to the distance from the ocean and elevation above sea level.
The highest and lowest temperatures become more extreme as the humidity decreases traveling away from the coast inland.
Usually, the humidity, although higher at the coast than in the hills, is still in the comfortable range.
Influence of the Marine Layer
A marine layer is an air mass sandwiched between the surface of a cool body of water and warm air.
Like a thick layer of fog, it only forms over the coastal regions in June, cooling the air below it.
Locals call it June Gloom but it is a natural air conditioner that lowers the humidity but it is disappearing.
LA has half the cloudy days it used to, causing the city to warm by 20F.
Fact: Los Angeles has an average temperature of roughly 18C, with August being the hottest month and averaging a high of 24.4C.
Topography and Microclimates
Los Angeles sits in a coastal basin with mountains to the north and east protecting it from weather extremes such as high temperatures brought in by winds like the Santa Ana.
This hot, dry, fast-moving air current arrives from the deserts of California and Arizona cooling as it crosses the mountains before dropping into the LA basin.
The interaction of the marine layer, the topography and the winds create a microclimate unique to the area.
Climate Change Effects
Los Angeles is experiencing heat waves and high relative humidity with such an increase in frequency people are noticing the impact of climate change.
The marine layer began its decline in 1970 making an impact on Los Angeles long before the public started taking it seriously.
The city struggled to improve its air quality by limiting pollutants from fossil fuels but with an increase in wildfires, it could be too late to save LA’s microclimate.
Fact: Los Angeles receives an average of 15 inches of rain annually, whereas the driest month of the city is July.
Effects of Humidity in Los Angeles
Many Los Angelenos admit to staying indoors to wait it out when it is hot rather than endure that sticky feeling.
Worldwide, many people are having to make decisions about how they have to manage life in a changing climate.
However, in California, the big cities are not predicted to become much more humid.
Nevertheless, the humidity levels in Los Angeles have an overall impact on the lives of people living here.
For instance:
Health and Comfort Implications
Los Angelenos are finding it hard to adjust to the unusual bouts of high humidity the city has begun experiencing more regularly.
There are implications for comfort and health because it also gets too low, occasionally as little as 11%.
When it is high, the resulting heat stress caused by the body’s inability to cool itself via sweating is life-threatening.
And if it is too low it affects the respiratory tract causing discomfort and trouble breathing.
Impact on Air Quality and Pollution
Poor air quality has been an issue for LA for many years but it brings more problems when the air is denser and slower moving during times of high humidity.
Pollutants including mold, dust mites, and other allergens remain suspended and trapped in the moisture rich air.
There are corresponding increases in asthma attacks and allergic reactions.
Bacteria and viruses breed faster and linger in the poorly circulating air longer affecting the population’s general health.
Influence on Plant Life and Ecosystems
Plant life struggles when humidity is high and whole ecosystems can die off.
Plants breathe by opening and closing stomata on the underside of their leaves. The process is also the plant’s cooling mechanism.
In warm weather, the stomata close to save water but can stay closed too long causing the plant to suffocate.
In high humidity, the water vapor blocks the stomata impeding vital evaporation that is part of the plant’s transpiration process.
Takeaway
Is Los Angeles humid? Traditionally, it has very nice weather with humidity in a comfortable range, but it is increasingly becoming humid recently.
Its coastal proximity, regional microclimates, and seasonal variations have a role to play in changing humidity.
Global warming has an impact as well, and the residents are definitely feeling the difference.
Therefore, understanding various factors affecting temperatures and humidity in Los Angeles is important, as it would help make changes to keep humidity within a normal range.
