NowClearTemperature 62°17°Rain chance 2%Wind 11 mph17 km/hNTrack temperature 73°23°
Mostly clearTemperature 60°16°Rain chance 3%Wind 10 mph17 km/hNNETrack temperature 66°19°
ClearTemperature 55°13°Rain chance 1%Wind 7 mph12 km/hNNETrack temperature 55°13°
ClearTemperature 52°11°Rain chance 0%Wind 6 mph9 km/hESETrack temperature 52°11°
OvercastTemperature 49°9°Rain chance 0%Wind 8 mph13 km/hSETrack temperature 49°9°
OvercastTemperature 47°9°Rain chance 0%Wind 9 mph14 km/hSETrack temperature 47°9°
FogTemperature 46°8°Rain chance 0%Wind 9 mph15 km/hSETrack temperature 46°8°
Partly cloudyTemperature 45°7°Rain chance 0%Wind 5 mph9 km/hSTrack temperature 45°7°
Mostly clearTemperature 43°6°Rain chance 0%Wind 7 mph11 km/hSSETrack temperature 43°6°
FogTemperature 43°6°Rain chance 0%Wind 8 mph13 km/hSSETrack temperature 43°6°
FogTemperature 44°7°Rain chance 0%Wind 8 mph13 km/hSSETrack temperature 44°7°
FogTemperature 44°7°Rain chance 0%Wind 7 mph12 km/hSTrack temperature 44°7°
FogTemperature 44°7°Rain chance 1%Wind 6 mph9 km/hSTrack temperature 44°7°
FogTemperature 44°7°Rain chance 1%Wind 8 mph13 km/hSTrack temperature 44°7°
OvercastTemperature 42°6°Rain chance 1%Wind 10 mph17 km/hSSETrack temperature 42°6°
FogTemperature 43°6°Rain chance 2%Wind 10 mph16 km/hSSETrack temperature 43°6°
FogTemperature 44°7°Rain chance 2%Wind 11 mph18 km/hSTrack temperature 44°7°
OvercastTemperature 46°8°Rain chance 2%Wind 12 mph19 km/hSTrack temperature 48°9°
OvercastTemperature 47°8°Rain chance 2%Wind 15 mph24 km/hSTrack temperature 49°9°
OvercastTemperature 49°9°Rain chance 3%Wind 16 mph26 km/hSTrack temperature 54°12°
OvercastTemperature 51°10°Rain chance 3%Wind 17 mph27 km/hSTrack temperature 57°14°
OvercastTemperature 52°11°Rain chance 2%Wind 18 mph29 km/hSTrack temperature 62°17°
OvercastTemperature 54°12°Rain chance 2%Wind 20 mph32 km/hSTrack temperature 66°19°
OvercastTemperature 54°12°Rain chance 2%Wind 19 mph31 km/hSTrack temperature 64°18°
Hours in your time zone (the track's when they match). Track temperature is an estimate.
Pit box
The racer numbers
Density altitude8,037ft2,450mField elevation 6,565 ft
Air density0.962kg/m³78.5% of standard (RAD)
Water grains41grgrains per lb of dry air
Track temp (est.)73°F23°CDirt in 372 W/m² sun
Dew point37°F3°C39% humidity
Barometer30.02inHg1017hPaRising over 3 h
SurfaceDryDry, likely dusty: little rain in 48 h
Rain, last 48 h0.0in0mmat the track
Computed from the forecast air temperature, dew point and station pressure (NWS formulas). Track temperature is estimated from sun, wind and the surface; it is not a sensor reading. How these are figured.
This week
Day by day
TodayOct 3163°17°42°6° 3%Green flag
TomorrowNov 154°12°42°6° 14%Yellow flag
MonNov 250°10°37°3° 58%Red flag
TueNov 357°14°37°3° 31%Green flag
WedNov 452°11°36°2° 17%Yellow flag
ThuNov 548°9°35°2° 12%Yellow flag
FriNov 656°13°38°4° 3%Green flagpartial
Day
Flag
Sky
High / low
Rain
Gusts
Track temp
Density alt.
Sunrise · sunset
Today Oct 31
Green flag
Fog
63°17°42°6°
3%
21 mph34 km/h S
86°30°
8,124 ft2,476 m
7:22 AM · 5:59 PM
Tomorrow Nov 1
Yellow flaggusty wind
Light drizzle
54°12°42°6°
14% 0.02 in0.4 mm
33 mph53 km/h S
66°19°
7,871 ft2,399 m
6:23 AM · 4:58 PM
Mon Nov 2
Red flagrain, gusty wind
Snow
50°10°37°3°
58% 0.97 in24.7 mm
55 mph89 km/h NNW
50°10°
7,755 ft2,364 m
6:24 AM · 4:56 PM
Tue Nov 3
Green flag
Overcast
57°14°37°3°
31%
41 mph67 km/h WSW
79°26°
7,809 ft2,380 m
6:25 AM · 4:55 PM
Wed Nov 4
Yellow flaggusty wind
Light drizzle
52°11°36°2°
17% 0.01 in0.2 mm
41 mph67 km/h NNW
67°19°
7,785 ft2,373 m
6:26 AM · 4:54 PM
Thu Nov 5
Yellow flagcold
Overcast
48°9°35°2°
12% 0.02 in0.5 mm
39 mph62 km/h N
70°21°
7,242 ft2,207 m
6:28 AM · 4:53 PM
Fri Nov 6
Green flag
Mostly clear
56°13°38°4°
3%
12 mph19 km/h SW
76°25°
7,831 ft2,387 m
6:29 AM · 4:52 PM
Flags judge the racing hours, 9 am to 10 pm at the track. Days marked partial are at the edge of the forecast.
Today’s remaining 8 hours are free. Pro members get all seven days and the CSV.
Hour
Air
Dew pt
Humidity
Barometer
Density alt.
Air density kg/m³
Grains
Track temp (est.)
Wind
Rain
62°17°
37°3°
39%
30.02 inHg1017 hPa
8,037 ft2,450 m
0.962
41
73°23°
11 mph17 km/h N
2%
60°16°
39°4°
45%
30.04 inHg1017 hPa
7,931 ft2,417 m
0.965
44
66°19°
10 mph17 km/h NNE
3%
55°13°
41°5°
59%
30.08 inHg1019 hPa
7,664 ft2,336 m
0.973
48
55°13°
7 mph12 km/h NNE
1%
52°11°
42°5°
69%
30.10 inHg1019 hPa
7,476 ft2,279 m
0.979
49
52°11°
6 mph9 km/h ESE
0%
49°9°
42°6°
77%
30.12 inHg1020 hPa
7,314 ft2,229 m
0.984
50
49°9°
8 mph13 km/h SE
0%
47°9°
42°6°
82%
30.11 inHg1020 hPa
7,264 ft2,214 m
0.985
50
47°9°
9 mph14 km/h SE
0%
46°8°
45°7°
98%
30.11 inHg1020 hPa
7,194 ft2,193 m
0.987
56
46°8°
9 mph15 km/h SE
0%
45°7°
43°6°
93%
30.11 inHg1020 hPa
7,151 ft2,180 m
0.988
52
45°7°
5 mph9 km/h S
0%
Every hour from the forecast, the same arithmetic as the pit box above (NWS density-altitude formula; track temperature is an estimate). Hours in your time zone, the track’s when they match.
Raceway Weather Pro
Plan the whole week at Calhan
Pit box, all week
Every forecast hour for the next seven days at Calhan: density altitude, air density, grains, track temp and more, with a CSV for the tuning laptop.
Do the models agree?
ECMWF, GFS and ICON side by side for the next three racing days, so you know when the forecast is shaky.
Next 6 hours of rain
Rain in 15-minute steps for the next six hours at your tracks, refreshed every hour.
Alerts for your tracks
An email the morning a red or yellow flag is due at Calhan, and a heads-up three days out.
ClearTemperature 55°13°Rain chance 1%Wind 7 mph12 km/hNNETrack temperature 55°13°
OvercastTemperature 49°9°Rain chance 0%Wind 8 mph13 km/hSETrack temperature 49°9°
FogTemperature 46°8°Rain chance 0%Wind 9 mph15 km/hSETrack temperature 46°8°
Partly cloudyTemperature 45°7°Rain chance 0%Wind 5 mph9 km/hSTrack temperature 45°7°
OvercastTemperature 46°8°Rain chance 2%Wind 12 mph19 km/hSTrack temperature 48°9°
54°12° 42°6° 14%Yellow flag
50°10° 37°3° 58%Red flag