Casa Blanca Weather

Live from Stanford
Measured at the Casa Blanca Farmstead station, with a forecast tuned to our village.
Forecast updated Mon 28 Sep 2026, 06:05 SAST
page built 06:07 SAST · Mon 28 Sep

Now in Stanford

Measured, not predicted
8.8 °C
feels like 8.8 °C
Today so far: high 11.2° at 01:40 · low 8.4° at 05:50
Today · our forecast
22° 8°
💧 0% chance of rain · Gust 23 km/h sheltered · 58 open ground

Most weather apps show a predicted number for this time of day. The 'Now' reading here is measured live in Stanford.

Humidity
94 %
Wind
1.4 km/h
Gust (today's max)
1.8 (5.4) km/h
Wind from
S 184°
Rain today
0.0 mm
Pressure
1019 hPa
Measured Mon 28 Sep 2026, 06:04 SAST at the Casa Blanca Farmstead station. The wind sensor sits among windbreak trees, so it reads lower than open ground.

Our 10-day forecast

🌬 Wind gusts: Sheltered is our gust forecast for the station, which sits among windbreak trees. Open ground is the raw ECMWF gust, a better guide for open, exposed plots.

Today28 Sep
22°8°
💧 0% chance · 0.0 mm
wind from SSE
Gust (daily max)
Sheltered23 km/h
Open ground58 km/h
ECMWF forecast: 20° / 10° · 0.0 mm
85% confident
Tomorrow29 Sep
25°12°
💧 0% chance · 0.0 mm
wind from SSE
Gust (daily max)
Sheltered26 km/h
Open ground66 km/h
ECMWF forecast: 24° / 12° · 0.0 mm
80% confident
Wednesday30 Sep
33°12°
💧 0% chance · 0.0 mm
wind from ESE
Gust (daily max)
Sheltered21 km/h
Open ground55 km/h
ECMWF forecast: 33° / 13° · 0.0 mm
70% confident
Thursday1 Oct
29°14°
💧 2% chance · 0.0 mm
wind from NW
Gust (daily max)
Sheltered16 km/h
Open ground32 km/h
ECMWF forecast: 33° / 16° · 0.0 mm
55% confident
Friday2 Oct
21°12°
💧 44% chance · 1.3 mm
wind from NW
Gust (daily max)
Sheltered19 km/h
Open ground50 km/h
ECMWF forecast: 22° / 15° · 1.2 mm
45% confident
Saturday3 Oct
19°10°
💧 56% chance · 3.0 mm
wind from SSW
Gust (daily max)
Sheltered19 km/h
Open ground44 km/h
ECMWF forecast: 18° / 12° · 1.5 mm
45% confident
Sunday4 Oct
25°11°
💧 26% chance · 0.2 mm
wind from SSE
Gust (daily max)
Sheltered19 km/h
Open ground40 km/h
ECMWF forecast: 20° / 11° · 0.9 mm
40% confident
Monday5 Oct
26°12°
💧 3% chance · 0.0 mm
wind from NW
Gust (daily max)
Sheltered17 km/h
Open ground39 km/h
ECMWF forecast: 23° / 10° · 0.0 mm
25% confident
Tuesday6 Oct
21°10°
💧 34% chance · 3.4 mm
wind from WNW
Gust (daily max)
Sheltered16 km/h
Open ground45 km/h
ECMWF forecast: 25° / 12° · 0.0 mm
25% confident*
Wednesday7 Oct
19°9°
💧 43% chance · 7.9 mm
wind from NW
Gust (daily max)
Sheltered19 km/h
Open ground65 km/h
ECMWF forecast: 16° / 10° · 12.9 mm
20% confident*
High / low °C from our forecast💧 chance of rain · amount Arrow points the way the wind blows; letters say where it comes from

Confidence = how often our past forecasts this many days ahead landed within 2 °C of what the station measured (* = estimated, see How this works).

Charts

Temperature: our forecast vs ECMWF

Temperature: our forecast high and low with likely range, and the ECMWF forecast, °CToday: high 21.6 (20.8–22.5), low 8.4 (8.4–9.3) °C; ECMWF 20.4/10.4Tomorrow: high 25.2 (24.6–26.2), low 12.2 (11.7–12.6) °C; ECMWF 23.8/12.4Wed 30 Sep: high 32.7 (31.5–33.5), low 12.0 (10.8–13.1) °C; ECMWF 33.2/13.0Thu 1 Oct: high 28.9 (24.6–32.8), low 14.4 (13.5–15.1) °C; ECMWF 33.0/16.2Fri 2 Oct: high 20.8 (18.5–22.0), low 11.7 (10.6–13.7) °C; ECMWF 21.7/14.6Sat 3 Oct: high 18.6 (16.7–21.0), low 10.1 (7.8–12.6) °C; ECMWF 17.9/11.5Sun 4 Oct: high 25.0 (20.5–27.9), low 11.2 (10.2–12.4) °C; ECMWF 19.6/11.4Mon 5 Oct: high 25.9 (23.6–28.2), low 11.5 (10.1–12.9) °C; ECMWF 22.6/10.5Tue 6 Oct: high 21.1 (16.8–25.4), low 10.3 (9.8–10.9) °C; ECMWF 24.6/12.0Wed 7 Oct: high 18.6 (16.5–20.7), low 8.9 (8.6–9.3) °C; ECMWF 15.7/9.7010203040°CMon28Tue29Wed30Thu1Fri2Sat3Sun4Mon5Tue6Wed7Temperature: our forecast high and low with likely range, and the ECMWF forecast, °CToday: high 21.6 (20.8–22.5), low 8.4 (8.4–9.3) °C; ECMWF 20.4/10.4Tomorrow: high 25.2 (24.6–26.2), low 12.2 (11.7–12.6) °C; ECMWF 23.8/12.4Wed 30 Sep: high 32.7 (31.5–33.5), low 12.0 (10.8–13.1) °C; ECMWF 33.2/13.0Thu 1 Oct: high 28.9 (24.6–32.8), low 14.4 (13.5–15.1) °C; ECMWF 33.0/16.2Fri 2 Oct: high 20.8 (18.5–22.0), low 11.7 (10.6–13.7) °C; ECMWF 21.7/14.6Sat 3 Oct: high 18.6 (16.7–21.0), low 10.1 (7.8–12.6) °C; ECMWF 17.9/11.5Sun 4 Oct: high 25.0 (20.5–27.9), low 11.2 (10.2–12.4) °C; ECMWF 19.6/11.4Mon 5 Oct: high 25.9 (23.6–28.2), low 11.5 (10.1–12.9) °C; ECMWF 22.6/10.5Tue 6 Oct: high 21.1 (16.8–25.4), low 10.3 (9.8–10.9) °C; ECMWF 24.6/12.0Wed 7 Oct: high 18.6 (16.5–20.7), low 8.9 (8.6–9.3) °C; ECMWF 15.7/9.7010203040°CMon28Tue29Wed30Thu1Fri2Sat3Sun4Mon5Tue6Wed7
Our highHigh: likely rangeOur lowLow: likely rangeECMWF highECMWF low

Rain: amount and chance

Rain: our forecast and the ECMWF forecast amounts (mm), wettest model, and chance of rain (%)Today: our forecast 0.0 mm (range 0.0–0.0), chance 0%; ECMWF 0.0 mmTomorrow: our forecast 0.0 mm (range 0.0–0.0), chance 0%; ECMWF 0.0 mmWed 30 Sep: our forecast 0.0 mm (range 0.0–0.0), chance 0%; ECMWF 0.0 mmThu 1 Oct: our forecast 0.0 mm (range 0.0–0.0), chance 2%; ECMWF 0.0 mmFri 2 Oct: our forecast 1.3 mm (range 0.0–4.0), chance 44%; ECMWF 1.2 mmSat 3 Oct: our forecast 3.0 mm (range 0.0–6.0), chance 56%; ECMWF 1.5 mmSun 4 Oct: our forecast 0.2 mm (range 0.0–0.5), chance 26%; ECMWF 0.9 mmMon 5 Oct: our forecast 0.0 mm (range 0.0–0.0), chance 3%; ECMWF 0.0 mmTue 6 Oct: our forecast 3.4 mm (range 0.0–6.7), chance 34%; ECMWF 0.0 mmWed 7 Oct: our forecast 7.9 mm (range 0.0–15.8), chance 43%; ECMWF 12.9 mm051015200255075100mmchance %Mon28Tue29Wed30Thu1Fri2Sat3Sun4Mon5Tue6Wed7Rain: our forecast and the ECMWF forecast amounts (mm), wettest model, and chance of rain (%)Today: our forecast 0.0 mm (range 0.0–0.0), chance 0%; ECMWF 0.0 mmTomorrow: our forecast 0.0 mm (range 0.0–0.0), chance 0%; ECMWF 0.0 mmWed 30 Sep: our forecast 0.0 mm (range 0.0–0.0), chance 0%; ECMWF 0.0 mmThu 1 Oct: our forecast 0.0 mm (range 0.0–0.0), chance 2%; ECMWF 0.0 mmFri 2 Oct: our forecast 1.3 mm (range 0.0–4.0), chance 44%; ECMWF 1.2 mmSat 3 Oct: our forecast 3.0 mm (range 0.0–6.0), chance 56%; ECMWF 1.5 mmSun 4 Oct: our forecast 0.2 mm (range 0.0–0.5), chance 26%; ECMWF 0.9 mmMon 5 Oct: our forecast 0.0 mm (range 0.0–0.0), chance 3%; ECMWF 0.0 mmTue 6 Oct: our forecast 3.4 mm (range 0.0–6.7), chance 34%; ECMWF 0.0 mmWed 7 Oct: our forecast 7.9 mm (range 0.0–15.8), chance 43%; ECMWF 12.9 mm051015200255075100mmchance %Mon28Tue29Wed30Thu1Fri2Sat3Sun4Mon5Tue6Wed7
Our rain (mm)ECMWF rain (mm)Wettest model (mm)Chance of rain (%, right axis)

Wind gusts: sheltered vs open ground

Wind gusts: sheltered (our forecast, with likely range) vs open ground (raw ECMWF), km/h; strong-wind line at 35 km/hstrong wind 35Today: sheltered gust 23 km/h (21–26), from SSE; open ground 58 km/hTomorrow: sheltered gust 26 km/h (24–28), from SSE; open ground 66 km/hWed 30 Sep: sheltered gust 21 km/h (15–23), from ESE; open ground 55 km/hThu 1 Oct: sheltered gust 16 km/h (12–21), from NW; open ground 32 km/hFri 2 Oct: sheltered gust 19 km/h (15–22), from NW; open ground 50 km/hSat 3 Oct: sheltered gust 19 km/h (17–21), from SSW; open ground 44 km/hSun 4 Oct: sheltered gust 19 km/h (15–24), from SSE; open ground 40 km/hMon 5 Oct: sheltered gust 17 km/h (15–19), from NW; open ground 39 km/hTue 6 Oct: sheltered gust 16 km/h (14–18), from WNW; open ground 45 km/hWed 7 Oct: sheltered gust 19 km/h (12–26), from NW; open ground 65 km/h020406080km/hMon28Tue29Wed30Thu1Fri2Sat3Sun4Mon5Tue6Wed7Wind gusts: sheltered (our forecast, with likely range) vs open ground (raw ECMWF), km/h; strong-wind line at 35 km/hstrong wind 35Today: sheltered gust 23 km/h (21–26), from SSE; open ground 58 km/hTomorrow: sheltered gust 26 km/h (24–28), from SSE; open ground 66 km/hWed 30 Sep: sheltered gust 21 km/h (15–23), from ESE; open ground 55 km/hThu 1 Oct: sheltered gust 16 km/h (12–21), from NW; open ground 32 km/hFri 2 Oct: sheltered gust 19 km/h (15–22), from NW; open ground 50 km/hSat 3 Oct: sheltered gust 19 km/h (17–21), from SSW; open ground 44 km/hSun 4 Oct: sheltered gust 19 km/h (15–24), from SSE; open ground 40 km/hMon 5 Oct: sheltered gust 17 km/h (15–19), from NW; open ground 39 km/hTue 6 Oct: sheltered gust 16 km/h (14–18), from WNW; open ground 45 km/hWed 7 Oct: sheltered gust 19 km/h (12–26), from NW; open ground 65 km/h020406080km/hMon28Tue29Wed30Thu1Fri2Sat3Sun4Mon5Tue6Wed7
Sheltered gust (our forecast)Sheltered: likely rangeOpen-ground gust (ECMWF)Strong-wind line 35 km/h

Dotted line = strong-wind warning level (35 km/h sheltered gust). Exact numbers are on the 10-day cards.

How this works

Our forecast takes four global weather models, checks each one against three years of readings from the Casa Blanca Farmstead station, corrects their usual mistakes for this spot and combines them. The ECMWF forecast is the leading global model on its own, without local correction, shown for comparison. Only the Now panel is measured; everything else is a forecast.

Typical miss over the past yearOur forecastECMWF forecast
Tomorrow's high1.0 °C1.8 °C
Tomorrow's low1.2 °C1.8 °C
Rain amount on wet days3.3 mm3.5 mm

Typical miss = how far the forecast usually ends up from what the station actually measured (smaller is better).

📄 Methods and verification: station siting, models, corrections, temperature and rain verification, and limitations (for hydrologists and meteorologists).

Accuracy details and technical notes

ECMWF is the European weather model (from the European Centre for Medium-Range Weather Forecasts) that most weather apps use; we show its raw numbers for comparison, before our station corrections.

Accuracy details

Live verification of issued forecasts (micro-local v2 vs raw ECMWF, by lead time)

Accuracy by lead time: typical miss (MAE, °C) of micro-local vs raw ECMWF highs and lowslead 0 d (n=1): high micro 0.61 / ECMWF 2.01; low micro 1.09 / ECMWF 2.69 °C0123MAE °C0n=1Accuracy by lead time: typical miss (MAE, °C) of micro-local vs raw ECMWF highs and lowslead 0 d (n=1): high micro 0.61 / ECMWF 2.01; low micro 1.09 / ECMWF 2.69 °C0123MAE °C0n=1
Micro highECMWF raw highMicro lowECMWF raw low

x axis: lead time in days (n = verified days).

Lead (d)nHigh °CLow °CRain mmGust km/h
microECMWFmicroECMWFmicroECMWFmicroECMWF*
010.612.011.092.691.101.900.621.4

Typical miss = mean absolute error against the station's complete days. Green = micro-local beat raw ECMWF. 1 verified forecast-days so far; small samples are noisy.

Backtest headline: test year 1 Oct 2025 – 25 Sep 2026 (corrections trained on data up to 30 Sep 2025)

MeasureMicro-localRaw ECMWFn days
Daily high, day-ahead (°C)MAE 1.01, bias +0.04MAE 1.77, bias -1.26359
Daily high, same-day issue (°C)MAE 0.98, bias +0.03–359
Daily low, day-ahead (°C)MAE 1.21, bias -0.13MAE 1.75, bias +1.40359
Daily low, same-day issue (°C)MAE 0.86, bias -0.41–359
Rain yes/no ≥0.5 mm (skill score HSS, higher is better)HSS 0.70 (hit rate 85%, false alarms 28%)HSS 0.69 (hit rate 87%, false alarms 30%)359
Rain amount on wet days (mm)MAE 3.27, bias -0.82MAE 3.52, bias -1.75
Daily max gust at the station (km/h)MAE 3.7, bias -2.4MAE 22.8, bias +22.8*359
Max hourly wind speed at the station (km/h)MAE 1.3, bias -0.5MAE 14.3, bias +14.3*359
Afternoon wind direction (station vane)MAE 54°, 52% within 45°MAE 70°, 36% within 45°327
Strong-wind days (station gust ≥40 km/h)2 hits, 3 misses, 0 false alarms5 hits, 0 misses, 218 false alarms (≥40)

MAE = typical miss; bias = forecast minus station (negative = forecast too low). *Raw ECMWF wind is an open-ground 10 m value, so most of its "error" against this sheltered 2.5 m anemometer is the site effect, not a model failure; for exposed open ground, spraying or fire risk, use the raw ECMWF gust as the guide. The strong-wind flag fires when the site gust forecast is ≥ 35 km/h; the corrected blend underestimates the very strongest days. Sources: summary.md, wind_summary.md, micro_forecasts/v2_validation.json.

Confidence by days ahead

Leaddayswithin ±2 °Cboth, by model spread
high+lowhighlownarrowmiddlewide
Today36077%90%86%87%75%69%
Tomorrow36071%87%81%79%72%61%
2 days ahead36068%85%80%75%71%59%
3 days ahead36064%81%78%81%57%55%
4 days ahead36059%77%77%70%59%47%
5 days ahead36051%72%72%61%48%46%
6 days ahead36043%62%66%50%38%42%
7 days ahead35834%55%63%40%37%26%
8 days aheadest.32%49%60%37%31%27%
9 days aheadest.26%42%56%31%26%22%
10 days aheadest.22%35%52%25%21%19%

Confidence = share of days with our corrected high AND low both within ±2 °C of the station, from re-issuing our v2 forecast for every complete station day 2025-10-01 – 2026-09-26 (out of sample: corrections trained up to 30 Sep 2025) using the models' archived runs from that many days earlier (Open-Meteo Previous Runs API, leads 1–7; lead 0 = same-day forecast with the morning nowcast). The blend uses the models the live forecast has at each lead (UKMO to 5 days, ICON to 6). Each day card shows the rate for its lead and that day's model-spread tercile (spread = average of the high and low ranges across the corrected models; terciles per lead, used when a tercile has ≥ 30 days), rounded to 5 % and kept within 10–95 %. Leads marked "est." have no archived forecasts and are estimated: weighted least squares, logit(hit rate) = a + b*lead over measured leads 1-7 (a = 1.2713, b = -0.2562), with the spread terciles scaled by the average tercile/lead ratio of leads 1–7 (1.17, 0.97, 0.86). Source: confidence.json (confidence.py, generated 2026-09-27 10:09).

Model notes

  • Today: rolling30_hi_bias=+0.87 (n=30); nowcast: station min 8.4 so far (to 06:00, 73 pts) · models bm+gfs+icon+ukmo
  • Tomorrow: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs+icon+ukmo
  • Wed 30 Sep: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs+icon+ukmo
  • Thu 1 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs+icon+ukmo
  • Fri 2 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs+icon+ukmo
  • Sat 3 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs+icon+ukmo
  • Sun 4 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs+icon
  • Mon 5 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs
  • Tue 6 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs
  • Wed 7 Oct: rolling30_hi_bias=+0.87 (n=30) · models bm+gfs

Method

Our forecast ("micro-local v2") = four global models (ECMWF, GFS, ICON, UKMO via Open-Meteo), each corrected against three years of this station's records and blended (rolling 30-day high bias, same-day nowcast, quantile-mapped rain, linear wind corrections with a +67° vane rotation). The ECMWF forecast is raw ECMWF IFS. Sheltered gust is the daily max gust the station's anemometer at 2.5 m behind windbreak trees will record, usually well under half the open-ground value; open ground is the raw ECMWF 10 m gust. Station ISTANF10 · Casa Blanca Farmstead, Stanford, Western Cape. Times are SAST. Source file: issued_2026-09-28_v2.csv.