MillbankPWS — WXSIM & WU Forecast vs Actual

Forecast initialized

2026-10-25 01:50

Forecast frozen

2026-10-25 02:30:03

Actual observations

1 of 7 days

+ today so far (provisional), updated 09:04

Actuals last updated

2026-10-26 06:00

WU forecast captured

2026-10-25 07:00:02

WU forecast status

7 of 7 days frozen — complete

Comparison:

WXSIM FORECAST

WU FORECAST

ACTUAL

WXSIM values come from latest.csv, frozen at capture. WU values come from the Weather Underground 5-day forecast: days 1–6 frozen on the start-day morning, day 7 added from the next morning's forecast. Actuals are Weather Underground PWS observations: completed days are written from 06:00 the following morning; today's pale bars (*) are provisional running values refreshed every 30 minutes and are not scored.

WXSIM v Weather Underground — Head-to-Head

Variable	Days compared	WXSIM mean abs. error	WU mean abs. error	Closer forecast
Maximum temperature	1	0.5 °C	0.5 °C	Level
Minimum temperature	1	1.3 °C	0.1 °C	WU
Rainfall	1	9.7 mm	0.9 mm	WU
Maximum sustained wind	1	3.6 mph	3.7 mph	WXSIM
Additional metrics forecast by both (mean absolute error; not included in the average error % below)
Mean relative humidity	1	12 %	10 %	WU
Maximum UV index	1	0.3	0.0	WU
Mean wind direction	1	13 °	2 °	WU
Minimum wind chill	1	1.5 °C	0.7 °C	WU
Maximum heat index	1	0.5 °C	0.5 °C	Level
Average error % (same days & variables)		22.3%	6.0%	WU

Only days on which WXSIM, WU and the actual observation all exist are scored, so both forecasts are compared on identical ground. The average error % uses High, Low, Rain and Wind. The WU daily forecast has no gust, solar radiation, dew point, wet bulb or pressure values, so those remain WXSIM-only.

Maximum & Minimum Temperature

WXSIM and WU forecasts versus actual daily temperature (°C)

Rainfall

WXSIM and WU forecasts versus actual daily total (mm)

Maximum Sustained Wind

WXSIM and WU forecasts versus actual (mph)

Maximum Wind Gust

WXSIM forecast versus actual — the WU daily forecast does not include gusts (mph)

WU forecast: not available — the Weather Underground 5-day forecast contains no gust values

Maximum Solar Radiation

WXSIM forecast versus actual daily maximum — not included in the WU daily forecast (W/m²)

WU forecast: not available — the Weather Underground 5-day forecast contains no solar radiation values

Additional Metrics — forecast by both WXSIM and WU

Actuals are the station's daily record; today's pale bars (*) are provisional and refreshed every 30 minutes.

Mean Relative Humidity

WXSIM and WU forecasts versus actual (%)

Maximum UV Index

WXSIM and WU forecasts versus actual (index)

Mean Wind Direction

WXSIM and WU forecasts versus actual (°)

Minimum Wind Chill

WXSIM and WU forecasts versus actual (°C)

Maximum Heat Index

WXSIM and WU forecasts versus actual (°C)

7-Day Values

Date	High °C					Low °C					Rain mm					Wind mph					Gust mph			Solar W/m²			Daily Error %
Date	WXSIM	WU	Actual	WXSIM Err %	WU Err %	WXSIM	WU	Actual	WXSIM Err %	WU Err %	WXSIM	WU	Actual	WXSIM Err %	WU Err %	WXSIM	WU	Actual	WXSIM Err %	WU Err %	WXSIM	Actual	Error %	WXSIM	Actual	Error %	WXSIM	WU
Sun 25 Oct	9.0	9.0	9.5	5.4%	5.4%	5.6	7.0	6.9	20.8%	1.4%	23.4	14.6	13.7	52.2%	6.5%	32.3	32.3	36.0	10.7%	10.7%	41.8	36.0	14.9%	120.0	376.0	103.2%	34.5%	6.0%
Mon 26 Oct	9.3	15.0	8.2*	—	—	4.6	5.0	4.9*	—	—	1.9	6.9	0.3*	—	—	19.2	18.0	13.0*	—	—	25.8	19.0*	—	56.4	72.0*	—	—	—
Tue 27 Oct	10.9	15.0	—	—	—	8.2	8.0	—	—	—	6.3	4.8	—	—	—	18.2	23.6	—	—	—	25.9	—	—	164.8	—	—	—	—
Wed 28 Oct	10.3	13.0	—	—	—	7.3	8.0	—	—	—	5.7	0.3	—	—	—	12.8	14.9	—	—	—	20.4	—	—	186.9	—	—	—	—
Thu 29 Oct	12.6	14.0	—	—	—	7.5	9.0	—	—	—	0.0	0.0	—	—	—	6.7	9.9	—	—	—	12.7	—	—	255.8	—	—	—	—
Fri 30 Oct	12.2	13.0	—	—	—	9.2	9.0	—	—	—	2.5	3.4	—	—	—	7.6	8.1	—	—	—	12.9	—	—	120.3	—	—	—	—
Sat 31 Oct	11.4	11.0	—	—	—	8.2	6.0	—	—	—	4.5	0.6	—	—	—	13.5	6.8	—	—	—	21.6	—	—	252.8	—	—	—	—
Average error for completed days in this forecast period																											34.5%	6.0%

Error % uses a symmetric forecast-versus-actual percentage difference (0% = exact match; maximum 200%). WXSIM Daily Error % is the mean of the available High, Low, Rain, Wind, Gust and Solar errors; WU Daily Error % is the mean of High, Low, Rain and Wind (WU supplies no gust or solar forecast) — use the Head-to-Head panel for a like-for-like comparison. pending = WU day 7 awaiting the next morning's capture; * = today so far, provisional (refreshed every 30 minutes, not scored); n/c = not captured (date had passed before WU capture began). Temperature percentages near freezing (0 °C / 32 °F) can appear large and should be interpreted as a comparative forecast-error indicator.

Frozen WXSIM latest.csv and Weather Underground 5-day forecasts compared with Weather Underground PWS observations.
Archive: 2026-10-25.json | WU archive: wu_weeks/2026-10-25.json | Display units: uk | Station timezone: Europe/London
WXSIM CSV Forecast vs Weather Underground Actuals — developed by MillbankPWS, Munlochy, Scotland

MillbankPWS — WXSIM & Weather Underground Forecasts vs Actual Weather

WXSIM v Weather Underground — Head-to-Head

Additional Metrics — forecast by both WXSIM and WU

7-Day Values