Significant Fire Potential is projected to be normal during April which means minimal activity then the above normal area increases from May through July as the fuel bed becomes more flammable and aligns with critical weather patterns.
Weather patterns are likely to be warmer and drier than normal during the next 3 months across most locations with July being a wildcard in terms of convective/lightning activity.
Alignment of critically dry dead-live fuels is expected to become more noticeable as the period progresses although initial barriers to fire spread will occur due to either melting snow or green-up.
Abundant herbaceous fuels will noticeably cure across the lower elevations during April-May therefore creating an increase in spread potential and fire business.
Weather Discussion
March was unusually warm and dry due to extended atmospheric blocking periods that led to strong ridge influences. The most impactful precipitation events occurred during the beginning and end of the month. Precipitation anomalies were generally below to well below normal. A historic spring heat wave event occurred during the latter half of the month. Record high temperatures were broken each day somewhere in northern CA between the 15th to 29th with the only exception being the 26th. Several locations broke their all-time March highs. Average temperatures were generally above to well above normal although near normal was found across portions of the North Coast. Nearly 220 lightning strikes were observed using the Vaisala detection system. The 2000-2025 Vaisala average is 676. There were 4 dry northerly and easterly wind periods with the strongest being on the 26th. There were 3 gusty westerly wind events with low to marginally low humidity readings. No National Weather Service Red Flag Warnings or Predictive Service High Risks were issued.
A warmer and drier than normal tilt to the weather patterns is expected from April through June. Some of the analog years and most of the dynamic climate models suggest active lightning potential during July which could create an unusual amount of ignitions. If ENSO transitions to El Nino during the next few months, tropical storm activity across the east Pacific should be robust and could portend a few moisture intrusions northward. The number of dry-wind events, both onshore and offshore, should be in the normal range during the next few months. Extended heat wave events are likely.
Fuels Discussion
Dead fuel flammability increased during March and became historically flammable during the latter half of March. The early growing season continued to transition up the slopes with shrub and tree canopy green-up as high as 4500-5500 ft and as high as 6000-7000 ft in the herbaceous fuel bed although dependent on sun exposure and when the snow went off.
The blue line found on the North Ops 1000-hour dead fuel moisture chart (Fig 6) shows unusually flammable values during most of March and reached the record minimum value on the 16th. Grey line is the historical average based on 18 years of data. The various color shading represents different flammability thresholds.
The lack of snow cover and an unusually early start to the growing season are the other significant storylines for this month.
Fig 8 illustrates the shrub green-up transition at 2 mid elevation locations therefore indicating changing flammability in many of the shrub species. Shrub vegetation remained dormant across the upper elevations. Herbaceous green-up was also evident across the exposed/snow free upper elevations during the latter portion of the month. The amount of moisture found within the snowpack and snow coverage area significantly lowered during the heat wave period.
Fig 9 illustrates the snowpack change between the 14th and 29th and shows snow water equivalent values on April 1st when moisture in the snowpack is typically the greatest. No drought conditions existed during March based on the US drought monitor although the abnormally dry classification grew noticeably across the north and east.
The two-month evaporative demand drought index (EDDI) value (Fig 7) on the 27th showed notable dryness markers across the near coastal areas and mountains.
NORTH OPS FIRE BUSINESS & TRENDS
Wildfire business grew during March with increased initial attack and spread after ignition. Several ignitions were due to escaped debris burns on private land. The daily wildfire ignition average was 5.1 and much higher compared to the February 2026 average of 0.8. March 2008-2025 daily ignition average is 2.3. The largest fire grew to 164 acres northeast of McArthur in a Tule marsh and became the first large fire of the season. The regional large fire average for March based on a 1992-2024 database is 0.30. The regional planning level (PL) remained at 1. Prescribed burning fluctuated between pile and underburn projects. During the heatwave event project implementation lessened due to heightened flammability and weather prescription restrictions. Projects noticeably increased at the end of the month, ahead of precipitation.
Based on the current fuel state and future weather predictions, normal large fire potential is projected for April due to a couple of barriers to fire spread including green-up and residual snow melt.
Above normal has been designated for the Sacramento Valley-Foothills and East Bay during May in anticipation that the near to above normal herbaceous fuel loading in those PSAs will be mostly cured and should be impacted by some gusty-dry wind periods. Historically May is typically a light large fire month.
During June, the above normal area expands across most of the region excluding the northwest corner where timely spring moisture intrusions are more likely therefore lessening the possibility of live fuel moisture stress. Elsewhere, curing should be evident across the low and mid elevations and combine with both onshore and offshore gusty-dry wind events. Large fire occurrence historically increases more noticeably from an average of 2 during May to 12 during June.
Critically flammable live and dead fuel alignments are likely to expand during July with large fire activity driven by a healthy mix of heat, wind and lightning. Live fuels across the highest elevations are likely to be less stressed during July although most of the snowpack should melt off during May which is unusually early by several weeks, if not a couple of months. Marine layer intrusions should be timely enough during July to lessen the large fire threat across the near Coastal areas.
Drought is likely to develop across portions of the region during the next 4 months. There will be several impactful wildcards to consider during the next few months including the potential of freeze killed fuels during April, due to cold periods following an unusual start to the growing season, rearrangement of the shrub-canopy fuels across the Sierra Foothills due to “snow crush” that occurred during the mid- February snow storm and herbaceous loading which includes the possibility of a second germination across some low elevation areas.