March smashed SLO County heat records. Here’s a look and what’s ahead
Last month will go down as one for the record books.
A strong high-pressure system anchored over the western United States produced an unprecedented heat wave, shattering thousands of daily high-temperature records and numerous all-time March records across the Western region.
Locally, the San Luis Obispo County Regional Airport typically averages a daytime high of 66.8 degrees in March. This year, the average high soared to 79 degrees, an astonishing 12.2 degrees above normal. The mean temperature reached 65.1, breaking the previous record of 61.8 set in 2004. The airport also recorded highs of 97 on both March 17 and 19, surpassing the previous daily record of 91.
At the Paso Robles Municipal Airport, the average high temperature climbed to 80.4, well above the normal 67.5. The mean temperature hit 61.9, exceeding the previous record of 59 degrees set in 2004. The airport also reached 95 twice during the month, breaking the long-standing daily record of 91 set on March 31, 1966.
The Santa Maria Public Airport also saw exceptional warmth. Its previous highest March mean temperature of 58.7 (set in 1998) was eclipsed by this year’s 63.2. On March 17, temperatures reached 95, tying the daily record set in 2015.
Farther south, North Shore in southeastern Riverside County reached a scorching 112 on March 20, setting a new California record for the hottest March temperature ever recorded.
In addition to the extreme heat, this persistent high-pressure system brought unusually dry conditions to the Central Coast. For only the fourth time since 1870, San Luis Obispo recorded no measurable rainfall during March, reducing seasonal totals at the airport to 91% of normal — down from 141% at the end of December.
Rainfall percentages also declined elsewhere.
Rocky Butte has recorded 33.02 inches this rain season (July 1 through June 30) or 94% of typical for this time of the year. Paso Robles dropped to 89% of normal, while Santa Maria, though still above average at 116%, fell sharply from 229% at the end of December.
The March heat wave also accelerated snowmelt in the Sierra Nevada. According to the California Department of Water Resources, as of April 1, 2026, the statewide snowpack stood at just 18% of average, making it the second-lowest on record. A record-hot March combined with rainfall rapidly diminished what had been a more promising start to the winter season.
This poses a serious concern. The Sierra snowpack functions as a natural reservoir, slowly releasing water through the spring and summer. This supply is critical for residential and agricultural use, hydroelectric power generation, ecosystem health, including fish habitats, and recreation.
True to form, April is a transitional month, caught somewhere between winter and summer. One day can bring stormy skies, while the next delivers near-record warmth, and this week’s forecast is shaping up to reflect that variability.
A warming trend will develop through Easter Sunday as high pressure builds over the Central Coast, generating gusty Santa Lucia (northeasterly) winds. These offshore winds will clear out the skies and drive temperatures 10 to 15 degrees above normal.
Coastal valleys like San Luis Obispo and inland areas such as Paso Robles are expected to reach the mid-80s, while beach communities could see highs in the upper 70s.
This time of year, when winds shift out of the northeast and blow from land to sea, they carry pollen from inland grasses, trees, and mountain vegetation toward the coast. As a result, communities across the Central Coast can expect elevated pollen levels.
By Monday, the high-pressure ridge will begin to weaken as a cold upper-level low moves south through Northern and Central California into midweek.
This system will bring increasing northwesterly winds along the Central Coast, ranging from fresh to strong (19 to 31 mph) levels, ushering in cooler marine air to San Luis Obispo and northern Santa Barbara counties. Night and morning low marine clouds will return, along with a noticeable drop in temperatures.
By Tuesday afternoon, winds could strengthen to strong to gale-force levels, with sustained speeds of 25 to 38 mph and gusts up to 45 mph.
As the system progresses through the region Thursday into Friday morning, moderate fresh (13 to 24 mph) southerly winds, increasing cloud cover, and rain are expected. Most areas are forecast to receive between a quarter and a half inch of rainfall.
Looking ahead, dry and breezy conditions are expected next weekend, with another potential chance of rain developing next Monday and Tuesday.
Surf report
This weekend’s 3- to 5-foot northwesterly (295-degree deep-water) sea and swell (with a 7- to 11-second period) will continue through Monday morning.
Increasing northwesterly winds along the California coastline will generate 5- to 7-foot northwesterly (300-degree deep-water) sea and swell (with a 5- to 11-second period) on Monday afternoon through Wednesday.
A 2- to 4-foot west-northwesterly (285-degree deep-water) swell (with an 8- to 14-second period) is forecast on Thursday, increasing to 5 to 7 feet next Saturday and Sunday.
Seawater temperatures will range between 55 to 57 degrees through Sunday, decreasing to 51 to 53 degrees later Monday and remaining at this level through Wednesday. Seawater temperatures will warm to 52 to 54 degrees on Thursday into next Sunday.
On this date in weather history, April 5
1945: The temperature at Eagles Nest, New Mexico, plunged to 45 degrees below zero to establish an April record for the United States. (Sandra and TI Richard Sanders, 1987)
1989: Unseasonably hot weather prevailed in the southwestern U.S. Afternoon highs of 100 degrees in Santa Maria and 105 degrees in downtown Los Angeles established records for the month of April. (The National Weather Summary)
2021: The long-range models indicated dry conditions would continue into the first half of April, if not longer, as the Central Coast moved toward the dryer months of May and June. If an atmospheric river (AR) rain event had not developed in late January, this would be one of the driest years on record since 1870 at Cal Poly. In fact, according to Jan Null at Golden Gate Weather Services, “The rainfall for the bulk of the last two seasons is now the second driest in 170 years of record for San Francisco.”
This week’s temperatures
LOWS AND HIGHS, PASO ROBLES
SUNDAY: 47, 85
MONDAY: 46, 80
TUESDAY: 44, 81
WEDNESDAY: 48, 73
THURSDAY: 44, 69
FRIDAY: 41, 71
SATURDAY: 45, 74
SUNDAY: 45, 76
LOWS AND HIGHS, SAN LUIS OBISPO AND COASTAL VALLEYS
SUNDAY: 55, 83
MONDAY: 52, 73
TUESDAY: 51, 76
WEDNESDAY: 53, 70
THURSDAY: 51, 68
FRIDAY: 52, 67
SATURDAY: 54, 68
SUNDAY: 55, 70
John Lindsey is a retired PG&E marine meteorologist. Email him at JohnLindseyLosOsos@gmail.com or follow him on X @PGE_John.