Photo: Der-wuppertaler · CC BY-SA 3.0Few U.S. towns have cooler summers than National City
On a normal January night the air cools to about 48°. Seasons differ by 29°, from the coldest nights to the warmest afternoons. It is a dry place: less rain and snow fall here than on 98% of U.S. towns. From January to December, highs of 65–77° make it easy to spend the day outdoors.
A year in National City at a glance
Each month’s typical high and low, and what it brings.
What stands out about National City’s climate
Compared with towns across the U.S., with National City’s place in California beside it.
What a year in National City feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Frost is rare
Frost and day counts come from NOAA’s station at Chula Vista, CA, 1.9 miles from the city’s center point, at about the same height.
The 2023 USDA map puts National City’s center in zone 10b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 37°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 9 inches of rain a year
February is the wettest month and July the driest. Rain falls on about 33 days a year. Snow is rare: about 0.0" in a normal year at Chula Vista, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in National City
65% of the work is heating. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Chula Vista, CA.
Living with National City’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10b. Frost comes about 1 winter in 14, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, May, June, July, August, September, October, November and December. 4.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in National City from natural hazards, earthquakes are the largest share (54%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →National City and its neighbors
Bonita has the coldest January nights next door (45°, 3° colder) and Bonita the hottest July afternoons (81°, 6° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like National City’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| National City, CA | 48° | 75° | 9" | 0.0" |
| Makawao, HI | 53° | 75° | 23" | 0.0" |
| Sequim, WA | 34° | 71° | 18" | 1.4" |
| Bethany, OR | 35° | 81° | 39" | 3.6" |
| Indian Hills, NV | 25° | 86° | 14" | 14" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in National City averaged 2.2° warmer than the 1900s. The biggest change is in January (+3.1°).
A bigger shift than in 95% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How National City compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with National City’s place among California’s.
National City weather by month
Highs, lows and precipitation from NOAA’s grid at National City’s center; snow, wet days and snow on the ground from Chula Vista, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 66° | 48° | 1.8" | 0.0" | 5 | 0 | 54° – 62° |
| February | 65° | 49° | 2.0" | 0.0" | 7 | 0 | 54° – 63° |
| March | 67° | 52° | 1.5" | 0.0" | 5 | 0 | 55° – 65° |
| April | 68° | 54° | 0.7" | 0.0" | 3 | 0 | 57° – 65° |
| May | 69° | 58° | 0.2" | 0.0" | 1 | 0 | 60° – 68° |
| June | 71° | 61° | 0.1" | 0.0" | 0 | 0 | 63° – 70° |
| July | 75° | 65° | 0.0" | 0.0" | 0 | 0 | 66° – 75° |
| August | 77° | 66° | 0.0" | 0.0" | 0 | 0 | 68° – 76° |
| September | 76° | 64° | 0.1" | 0.0" | 1 | 0 | 66° – 75° |
| October | 74° | 59° | 0.4" | 0.0" | 1 | 0 | 63° – 72° |
| November | 70° | 52° | 0.8" | 0.0" | 3 | 0 | 55° – 65° |
| December | 66° | 48° | 1.6" | 0.0" | 5 | 0 | 54° – 59° |
| Year | 70° | 56° | 9.1" | 0.0" | 33 | 0 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 55° to 65°. December is the most reliable, staying within 5°.
Where National City’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at National City’s center.
- Snow: Chula Vista, CA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Chula Vista, CA, 1.9 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about National City’s climate
What is the weather like in National City?
A typical July afternoon reaches 75°, a January night drops to 48°, and snow is almost unheard of. Milder January nights than 96% of U.S. towns; cooler July afternoons than all but 190 U.S. towns.
How cold does it get in National City in winter?
December nights average 48°. A night at 32° or below comes in only some winters (0.1 a year on average). In the coldest December of the last 30 years the month averaged 54°.
How much snow does National City get?
About 0.0 inches in a normal winter at Chula Vista, CA, so most winters see none.
How hot does it get in National City?
July, with a typical high of 75° and a low of 65°. About 5 days a year reach 90° (Chula Vista, CA).
When is the first and last frost in National City?
Most years have no frost at all: a 32° night comes in about 7% of winters at Chula Vista, CA, usually in December or January.
What growing zone is National City in?
Zone 10b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 37°.
What is the best time of year to visit National City?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, June, July, August, September, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is National City getting warmer?
Yes: 1991–2020 averaged 2.2° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 95% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in National City.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.