The Spread Maps Request an invite

Which weather model is most accurate in San Francisco?

Forecast Highs Lows Rain Model accuracy

San Francisco, California · daily high temperature in °F · trailing 30 days, through Fri Oct 16

Every day, The Spread archives what each major weather model predicted for San Francisco at 1-, 3-, and 7-day leads, then scores those forecasts against the SFOC1 observations once the day has happened. This page covers the trailing 30 days (2026-09-17 to 2026-10-16), for daily high temperature.

One day out, ECMWF IFS has been most accurate (typical miss 2.23°F); at three days, too close to call; at seven days, ECMWF AIFS (AI) (4.41°F).

The largest standing bias belongs to NOAA AIGFS (AI), which has run warm by about 4.25°F at 1-day lead over this window.

San Francisco's full forecast, every model day by day, with the record on this page beside it. Request an invite; it's free during the beta.

The scoreboard

Typical miss (MAE) in °F with the bias in parentheses. Bias is the mean signed error of the predicted daily high — positive means the model ran warm. A model's high is the warmest of its hourly values and the station's is the warmest it got at any moment, so a model's high reads a little cool, and its low a little warm, even on a day it gets every hour right. ECMWF IFS gives a value only every 3 hours (every 6 past day 6), and ECMWF AIFS (AI) and NOAA AIGFS (AI) only every 6, with the hours between filled in, so their highs read cooler still and their lows warmer. In the forecasts scored here GFS also steps to every 3 hours from day 5, ICON and GEM from day 4, and UKMO from day 3, every 6 by day 6. Days = scored days behind the 1-day number.

Model 1-day 3-day 7-day Days
ECMWF IFS 2.2° (-0.3°) 2.7° (-1.2°) 6.5° (-5.4°) 29
ECMWF AIFS (AI) 2.8° (+1.1°) 2.7° (+1.4°) 4.4° (-0.7°) 29
UKMO (UK) 3.0° (+1.4°) 3.5° (+1.7°) — 29
NOAA GFS 3.1° (+2.0°) 4.5° (+2.5°) 6.5° (+2.3°) 29
GEM (Canada) 3.5° (-1.9°) 4.0° (-1.9°) 5.1° (-2.5°) 29
DWD ICON 4.1° (-3.5°) 3.0° (-1.9°) — 29
NOAA AIGFS (AI) 4.6° (+4.2°) 4.9° (+4.2°) 5.8° (+3.1°) 29

Method, honestly

The Spread's San Francisco point is the Duboce Triangle station (SFOC1), 0.4 mi from downtown, used for both forecasts and verifications. Each forecast is the last one The Spread archived on the day it was made, the forecast the model was showing at the time, not a reconstruction. A day the station did not report is left out. Truth is the thermometer at Duboce Triangle (SFOC1) — the station's own daily highs, a thermometer rather than a grid, and no correction applies: the thermometer is the truth outright. Rankings cover the models themselves; consensus products such as the NBM, itself a blend of models, are not scored here. A rolling 30-day window means these numbers move — that is the point.

Receipts — was the forecast right?

One page per settled date: what every model said as the day approached, what happened, and who was closest.

  • Fri Oct 16 14 days out the models said 72–91; it hit 87. AIGFS led (off 0.8°F); GEM ran 12°F cool.
  • Thu Oct 15 14 days out the models said 63–79; it hit 83. UKMO led (off 0.2°F); GEM ran 6°F cool.
  • Wed Oct 14 14 days out the models said 63–74; it hit 71. ECMWF led (off 0.8°F); ICON ran 6°F cool.
  • Tue Oct 13 14 days out the models said 67–76; it hit 73. AIGFS led (off 0.1°F); GEM ran 8°F cool.
  • Mon Oct 12 14 days out the models said 60–78; it hit 66. GFS led (off 0.2°F); GEM ran 3°F cool.
  • Sun Oct 11 14 days out the models said 69–92; it hit 63. ECMWF led (off 0.2°F); GEM ran 2°F cool.
  • Sat Oct 10 14 days out the models said 71–83; it hit 62. AIGFS led (off 0.3°F); ICON ran 2°F cool.
  • Fri Oct 9 14 days out the models said 72–88; it hit 64. AIFS led (off 0.8°F); GFS ran 7°F warm.
  • Thu Oct 8 14 days out the models said 66–92; it hit 76. GFS led (off 0.0°F); ICON ran 15°F cool.
  • Wed Oct 7 14 days out the models said 67–89; it hit 71. ECMWF led (off 1.7°F); AIGFS ran 12°F warm.
  • Tue Oct 6 13 days out the models said 65–81; it hit 72. ICON led (off 0.1°F); AIGFS ran 14°F warm.
  • Mon Oct 5 14 days out the models said 68–87; it hit 71. ICON led (off 1.9°F); AIGFS ran 14°F warm.
  • Sun Oct 4 14 days out the models said 63–82; it hit 86. AIGFS led (off 0.1°F); ICON ran 10°F cool.
  • Sat Oct 3 14 days out the models said 68–91; it hit 91. AIGFS led (off 1.2°F); ICON ran 11°F cool.
  • Fri Oct 2 14 days out the models said 65–90; it hit 76. AIFS led (off 0.5°F); ICON ran 8°F cool.
  • Thu Oct 1 14 days out the models said 67–71; it hit 68. UKMO led (off 0.4°F); GFS ran 8°F warm.
  • Wed Sep 30 14 days out the models said 65–84; it hit 72. GEM led (off 0.6°F); AIGFS ran 10°F warm.
  • Tue Sep 29 14 days out the models said 62–76; it hit 74. AIFS led (off 0.9°F); AIGFS ran 6°F warm.
  • Mon Sep 28 14 days out the models said 62–89; it hit 69. AIGFS led (off 0.5°F); ICON ran 5°F cool.
  • Sun Sep 27 14 days out the models said 68–85; it hit 63. ECMWF led (off 0.0°F); UKMO ran 6°F warm.
  • Sat Sep 26 13 days out the models said 65–79; it hit 68. AIGFS led (off 1.2°F); ICON ran 6°F cool.
  • Fri Sep 25 14 days out the models said 68–76; it hit 67. GFS led (off 0.0°F); UKMO ran 9°F warm.
  • Thu Sep 24 14 days out the models said 66–84; it hit 75. AIFS led (off 1.4°F); ICON ran 10°F cool.
  • Wed Sep 23 14 days out the models said 70–84; it hit 75. GFS led (off 1.5°F); ICON ran 6°F cool.
  • Tue Sep 22 14 days out the models said 66–76; it hit 63. ICON led (off 0.1°F); GFS ran 6°F warm.
  • Mon Sep 21 14 days out the models said 65–82; it hit 61. UKMO led (off 0.3°F); AIGFS ran 5°F warm.
  • Sun Sep 20 14 days out the models said 69–87; it hit 60. UKMO led (off 0.7°F); AIGFS ran 7°F warm.
  • Sat Sep 19 14 days out the models said 62–69; it hit 66. ICON led (off 0.1°F); AIGFS ran 7°F warm.
  • Fri Sep 18 13 days out the models said 65–70; it hit 66. ECMWF led (off 0.1°F); AIGFS ran 7°F warm.
  • Thu Sep 17 14 days out the models said 64–85; it hit 70. GFS led (off 0.1°F); GEM ran 3°F cool.
  • Wed Sep 16 14 days out the models said 67–86; it hit 63. UKMO led (off 0.0°F); AIGFS ran 2°F warm.
  • Tue Sep 15 14 days out the models said 67–77; it hit 66. GEM led (off 0.7°F); GFS ran 6°F warm.
  • Mon Sep 14 14 days out the models said 65–94; it hit 71. ECMWF led (off 1.6°F); AIGFS ran 4°F warm.
  • Sun Sep 13 14 days out the models said 66–79; it hit 66. GFS led (off 0.7°F); UKMO ran 6°F warm.
  • Sat Sep 12 14 days out the models said 66–74; it hit 68. AIFS led (off 0.3°F); GEM ran 3°F cool.
  • Fri Sep 11 14 days out the models said 66–80; it hit 66. UKMO led (off 0.3°F); AIGFS ran 6°F warm.
  • Thu Sep 10 14 days out the models said 63–85; it hit 76. UKMO led (off 1.9°F); AIGFS ran 7°F warm.
  • Wed Sep 9 14 days out the models said 62–76; it hit 94. AIGFS led (off 0.5°F); GEM ran 12°F cool.
  • Tue Sep 8 14 days out the models said 65–71; it hit 85. AIFS led (off 0.3°F); ICON ran 10°F cool.
  • Mon Sep 7 14 days out the models said 63–74; it hit 81. AIGFS led (off 1.3°F); ICON ran 8°F cool.
  • Sun Sep 6 14 days out the models said 67–80; it hit 69. UKMO led (off 0.1°F); GEM ran 5°F cool.
  • Sat Sep 5 14 days out the models said 65–78; it hit 71. AIGFS led (off 0.4°F); ICON ran 7°F cool.
  • Fri Sep 4 13 days out the models said 66–74; it hit 68. AIFS led (off 0.3°F); GEM ran 3°F cool.
  • Thu Sep 3 12 days out the models said 66–72; it hit 71. GFS led (off 0.6°F); ICON ran 8°F cool.
  • Wed Sep 2 11 days out the models said 67–73; it hit 70. ECMWF led (off 0.4°F); ICON ran 3°F cool.
  • Tue Sep 1 10 days out the models said 65–72; it hit 69. GFS led (off 0.9°F); GEM ran 4°F cool.
  • Mon Aug 31 9 days out the models said 60–69; it hit 65. AIGFS led (off 0.0°F); GEM ran 3°F cool.
  • Sun Aug 30 8 days out the models said 62–70; it hit 65. ECMWF led (off 0.5°F); AIFS ran 3°F warm.
  • Sat Aug 29 7 days out the models said 60–73; it hit 66. GFS led (off 0.1°F); UKMO ran 5°F warm.
  • Fri Aug 28 6 days out the models said 61–75; it hit 68. AIFS led (off 0.9°F); AIGFS ran 6°F warm.
  • Thu Aug 27 5 days out the models said 67–80; it hit 70. ECMWF led (off 0.9°F); AIGFS ran 8°F warm.
  • Wed Aug 26 4 days out the models said 65–76; it hit 69. ICON led (off 0.8°F); AIGFS ran 11°F warm.
  • Tue Aug 25 3 days out the models said 64–74; it hit 70. GFS led (off 1.0°F); ICON ran 6°F cool.
  • Wed Aug 19 14 days out the models said 65–71; it hit 64. ICON led (off 1.0°F); AIGFS ran 11°F warm.
  • Tue Aug 18 14 days out the models said 65–73; it hit 64. GEM led (off 0.7°F); AIGFS ran 9°F warm.
  • Mon Aug 17 14 days out the models said 64–69; it hit 66. ECMWF led (off 0.2°F); AIGFS ran 8°F warm.
  • Sun Aug 16 14 days out the models said 65–73; it hit 65. GEM led (off 0.6°F); AIGFS ran 8°F warm.
  • Sat Aug 15 14 days out the models said 62–72; it hit 64. ECMWF led (off 0.6°F); AIGFS ran 4°F warm.
  • Fri Aug 14 14 days out the models said 65–75; it hit 65. AIFS led (off 0.0°F); AIGFS ran 2°F warm.
  • Thu Aug 13 14 days out the models said 62–74; it hit 66. GEM led (off 0.1°F); AIGFS ran 3°F warm.
  • Wed Aug 12 14 days out the models said 66–78; it hit 66. GEM led (off 0.7°F); AIGFS ran 5°F warm.
  • Tue Aug 11 14 days out the models said 62–72; it hit 65. ICON led (off 1.4°F); AIGFS ran 7°F warm.
  • Mon Aug 10 14 days out the models said 68–72; it hit 66. UKMO led (off 0.2°F); AIGFS ran 8°F warm.
  • Sun Aug 9 14 days out the models said 63–74; it hit 66. ICON led (off 1.9°F); AIGFS ran 18°F warm.
  • Sat Aug 8 13 days out the models said 64–75; it hit 62. ICON led (off 0.1°F); AIGFS ran 16°F warm.
  • Fri Aug 7 12 days out the models said 63–82; it hit 62. ICON led (off 1.5°F); AIGFS ran 15°F warm.
  • Thu Aug 6 11 days out the models said 66–83; it hit 65. ICON led (off 0.4°F); AIGFS ran 11°F warm.
  • Wed Aug 5 10 days out the models said 68–85; it hit 66. GFS led (off 0.2°F); AIGFS ran 10°F warm.
  • Tue Aug 4 9 days out the models said 67–84; it hit 67. ECMWF led (off 1.7°F); AIGFS ran 11°F warm.
  • Mon Aug 3 8 days out the models said 64–77; it hit 69. ICON led (off 2.4°F); GFS ran 15°F warm.
  • Sun Aug 2 7 days out the models said 66–81; it hit 72. GEM led (off 0.3°F); GFS ran 11°F warm.
  • Sat Aug 1 6 days out the models said 68–81; it hit 71. ECMWF led (off 1.3°F); AIGFS ran 10°F warm.
  • Fri Jul 31 5 days out the models said 64–79; it hit 69. ECMWF led (off 0.3°F); ICON ran 6°F cool.
  • Thu Jul 30 4 days out the models said 64–76; it hit 65. GEM led (off 0.4°F); AIGFS ran 9°F warm.

Other cities

Atlanta, Georgia Berlin, State of Berlin Boston, Massachusetts Buffalo, New York Charlotte, North Carolina Chicago, Illinois Dallas, Texas Denver, Colorado Detroit, Michigan Houston, Texas London, England Los Angeles, California Miami, Florida Milan, Lombardy Minneapolis, Minnesota New Orleans, Louisiana New York, New York Oklahoma City, Oklahoma Orlando, Florida Paris, Île-de-France Region Philadelphia, Pennsylvania Phoenix, Arizona Salt Lake City, Utah San Antonio, Texas San Diego, California Seattle, Washington St. Louis, Missouri Tampa, Florida Washington, District of Columbia

The Spread — the forecast spread — is in closed beta. These verification pages are public while the rest is gated.