Steamboat Springs
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Steamboat Springs clear sky chart from 2005-11-06 to 2025-11-18.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	4 10% 4 8% 5% 4 4 4 5% 7% 44%	135904
	Night	4 12% 5% 9% 5% 4 4 3 5% 6% 45%	131931
Transparency	Day	38% 5% 9% 23% 18% 7%	130793
	Night	40% 4 10% 23% 17% 6%	128046
Seeing	Day	12% 14% 30% 28% 14% 3	16998
	Night	12% 7% 25% 38% 17% 1	27053

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	2 15% 7% 22% 7% 3 3 2 4 5% 31%	3638
	11th to 20th	Day	2 13% 9% 17% 14% 6% 4 2 4 3 26%	3962
	21st to end	Day	2 16% 9% 14% 7% 4 3 2 3 4 37%	4510
February	1st to 10th	Day	6% 23% 7% 16% 5% 3 3 2 4 5% 26%	1800
	11th to 20th	Day	4 18% 11% 16% 5% 3 3 2 4 5% 29%	1803
	21st to end	Day	2 19% 8% 17% 6% 4 4 2 4 5% 28%	1650
March	1st to 10th	Day	2 15% 10% 13% 4 3 4 3 4 5% 37%	4725
	11th to 20th	Day	1 14% 7% 13% 4 4 3 3 4 6% 40%	5000
	21st to end	Day	3 24% 8% 13% 6% 4 4 3 4 5% 26%	5634
April	1st to 10th	Day	5% 17% 4 10% 4 4 3 3 6% 6% 37%	2400
	11th to 20th	Day	7% 17% 5% 9% 6% 5% 4 4 6% 7% 31%	2371
	21st to end	Day	5% 16% 4 7% 5% 5% 4 5% 6% 8% 36%	2400
May	1st to 10th	Day	6% 14% 5% 8% 5% 5% 6% 5% 7% 7% 33%	5889
	11th to 20th	Day	5% 10% 3 7% 5% 5% 6% 5% 7% 7% 40%	6298
	21st to end	Day	4 7% 2 5% 4 5% 5% 5% 7% 9% 45%	6925
June	1st to 10th	Day	4 5% 2 4 4 4 5% 5% 6% 8% 53%	2800
	11th to 20th	Day	5% 3 1 4 4 4 4 4 5% 8% 59%	2800
	21st to end	Day	3 3 1 4 4 3 5% 4 6% 8% 60%	2800
July	1st to 10th	Day	3 2 1 4 3 4 6% 4 6% 7% 59%	6339
	11th to 20th	Day	1 2 1 4 4 5% 6% 6% 8% 9% 53%	6340
	21st to end	Day	3 3 1 5% 4 6% 7% 5% 8% 9% 48%	6503
August	1st to 10th	Day	3 4 2 5% 5% 5% 5% 5% 7% 8% 51%	5779
	11th to 20th	Day	5% 4 2 5% 4 5% 5% 4 6% 8% 52%	5632
	21st to end	Day	7% 6% 3 7% 5% 5% 5% 4 6% 7% 46%	5984
September	1st to 10th	Day	5% 4 1 4 3 3 4 3 6% 7% 60%	2400
	11th to 20th	Day	6% 6% 2 5% 3 3 5% 3 6% 6% 55%	2400
	21st to end	Day	8% 5% 1 4 3 3 2 2 4 5% 61%	2132
October	1st to 10th	Day	6% 6% 1 3 2 2 3 2 3 4 69%	3270
	11th to 20th	Day	6% 8% 3 5% 3 3 3 3 5% 8% 52%	3250
	21st to end	Day	6% 14% 5% 5% 3 3 3 3 5% 5% 47%	3548
November	1st to 10th	Day	5% 12% 4 8% 3 3 3 3 5% 6% 49%	1871
	11th to 20th	Day	5% 16% 5% 9% 3 3 3 3 4 5% 43%	1801
	21st to end	Day	4 13% 6% 12% 3 2 2 1 4 6% 47%	1600
December	1st to 10th	Day	3 11% 4 15% 5% 2 2 2 2 4 50%	2620
	11th to 20th	Day	2 18% 8% 8% 3 2 2 2 3 5% 45%	3026
	21st to end	Day	3 20% 6% 14% 6% 4 4 3 4 6% 28%	4004
January	1st to 10th	Night	2 12% 9% 20% 7% 5% 3 3 4 4 29%	6327
	11th to 20th	Night	1 15% 9% 17% 11% 6% 3 3 3 4 29%	6049
	21st to end	Night	2 16% 8% 15% 6% 3 2 2 2 3 40%	6468
February	1st to 10th	Night	4 21% 8% 16% 6% 4 3 3 4 4 26%	2600
	11th to 20th	Night	5% 19% 9% 14% 5% 4 3 3 4 5% 30%	2482
	21st to end	Night	4 18% 8% 15% 6% 3 3 3 4 5% 32%	1980
March	1st to 10th	Night	2 17% 10% 11% 4 3 4 3 4 5% 38%	5157
	11th to 20th	Night	2 10% 5% 11% 4 4 4 3 4 6% 48%	5000
	21st to end	Night	5% 25% 7% 11% 4 4 3 3 4 5% 30%	5320
April	1st to 10th	Night	7% 16% 5% 7% 4 4 3 3 5% 5% 41%	2000
	11th to 20th	Night	7% 16% 6% 8% 3 4 4 3 5% 6% 38%	1977
	21st to end	Night	7% 15% 4 7% 4 3 4 3 5% 7% 41%	2000
May	1st to 10th	Night	6% 13% 5% 5% 4 4 5% 4 6% 7% 41%	4072
	11th to 20th	Night	7% 14% 3 7% 4 4 5% 4 6% 7% 37%	3617
	21st to end	Night	7% 9% 2 5% 3 3 3 3 5% 7% 51%	3972
June	1st to 10th	Night	5% 5% 2 4 3 3 4 4 6% 10% 55%	1600
	11th to 20th	Night	5% 4 2 5% 3 3 3 4 5% 7% 59%	1600
	21st to end	Night	3 3 1 4 2 2 4 3 5% 6% 66%	1600
July	1st to 10th	Night	4 3 1 5% 3 4 4 3 5% 6% 61%	3640
	11th to 20th	Night	1 2 1 5% 4 5% 6% 5% 9% 11% 51%	3640
	21st to end	Night	1 2 1 5% 5% 5% 6% 5% 8% 9% 55%	4352
August	1st to 10th	Night	4 4 2 6% 5% 5% 6% 4 8% 7% 50%	4033
	11th to 20th	Night	3 4 2 6% 4 4 5% 4 6% 7% 55%	4217
	21st to end	Night	5% 4 2 5% 4 5% 6% 4 7% 8% 48%	4993
September	1st to 10th	Night	4 4 1 5% 3 3 4 4 5% 6% 62%	2000
	11th to 20th	Night	5% 5% 2 4 3 3 4 3 4 7% 60%	2000
	21st to end	Night	8% 4 1 4 3 3 3 2 3 5% 64%	2263
October	1st to 10th	Night	5% 5% 1 3 2 2 3 2 4 4 69%	3920
	11th to 20th	Night	7% 7% 2 5% 3 4 3 3 4 7% 55%	3898
	21st to end	Night	7% 11% 4 6% 3 2 3 3 4 5% 53%	4252
November	1st to 10th	Night	5% 12% 3 7% 3 2 3 3 5% 6% 51%	2625
	11th to 20th	Night	5% 15% 4 9% 3 3 3 3 4 6% 45%	2752
	21st to end	Night	5% 12% 5% 9% 4 3 3 3 5% 6% 45%	2800
December	1st to 10th	Night	3 12% 4 11% 5% 3 2 2 3 3 52%	4570
	11th to 20th	Night	3 14% 8% 13% 5% 3 3 3 4 7% 36%	5181
	21st to end	Night	4 22% 7% 13% 6% 4 3 3 4 5% 29%	6974

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	55% 5% 11% 15% 12% 1	3639
	11th to 20th	Day	62% 5% 9% 12% 10% 2	3962
	21st to end	Day	51% 5% 9% 15% 13% 7%	4510
February	1st to 10th	Day	61% 5% 10% 14% 9% 2	1800
	11th to 20th	Day	58% 4 9% 19% 8% 2	1812
	21st to end	Day	55% 6% 10% 14% 12% 2	1650
March	1st to 10th	Day	47% 4 8% 22% 11% 8%	4725
	11th to 20th	Day	45% 5% 12% 30% 8% 1	5000
	21st to end	Day	57% 6% 11% 19% 6% 1	5634
April	1st to 10th	Day	45% 5% 13% 20% 14% 4	2400
	11th to 20th	Day	49% 6% 11% 20% 14% 1	2374
	21st to end	Day	44% 7% 10% 29% 11%	2400
May	1st to 10th	Day	44% 7% 9% 23% 16% 2	5889
	11th to 20th	Day	36% 7% 9% 30% 18% 1	6302
	21st to end	Day	31% 6% 9% 32% 22% 1	6926
June	1st to 10th	Day	26% 6% 13% 26% 21% 8%	2800
	11th to 20th	Day	23% 6% 8% 18% 30% 15%	2800
	21st to end	Day	21% 6% 5% 20% 31% 16%	2800
July	1st to 10th	Day	21% 4 5% 14% 27% 29%	6271
	11th to 20th	Day	25% 4 7% 24% 29% 11%	6265
	21st to end	Day	29% 4 9% 18% 24% 15%	6316
August	1st to 10th	Day	33% 6% 12% 20% 16% 13%	4208
	11th to 20th	Day	33% 5% 10% 19% 24% 9%	4079
	21st to end	Day	29% 5% 10% 20% 23% 14%	4311
September	1st to 10th	Day	24% 4 8% 19% 28% 18%	2400
	11th to 20th	Day	28% 5% 9% 22% 26% 10%	2400
	21st to end	Day	27% 3 5% 30% 29% 6%	2132
October	1st to 10th	Day	21% 3 5% 25% 35% 10%	3270
	11th to 20th	Day	31% 3 6% 36% 21% 3	3250
	21st to end	Day	39% 3 8% 36% 13% 2	3548
November	1st to 10th	Day	35% 5% 11% 27% 21% 1	1871
	11th to 20th	Day	41% 4 15% 23% 15% 1	1801
	21st to end	Day	40% 3 11% 29% 15% 2	1600
December	1st to 10th	Day	40% 3 12% 33% 11% 1	2620
	11th to 20th	Day	42% 3 18% 27% 8%	3024
	21st to end	Day	55% 6% 8% 18% 12% 1	4004
January	1st to 10th	Night	57% 3 9% 17% 9% 5%	6327
	11th to 20th	Night	61% 4 10% 13% 11% 2	6049
	21st to end	Night	51% 3 10% 14% 16% 6%	6468
February	1st to 10th	Night	61% 4 10% 16% 8% 1	2600
	11th to 20th	Night	55% 5% 9% 20% 9% 2	2483
	21st to end	Night	53% 5% 9% 16% 15% 2	1980
March	1st to 10th	Night	46% 6% 6% 22% 13% 7%	5157
	11th to 20th	Night	37% 4 10% 31% 17% 2	5000
	21st to end	Night	55% 4 13% 22% 5%	5320
April	1st to 10th	Night	42% 6% 11% 20% 17% 4	2000
	11th to 20th	Night	44% 6% 12% 22% 15% 2	1977
	21st to end	Night	41% 5% 10% 26% 17% 1	2000
May	1st to 10th	Night	36% 8% 11% 27% 16% 2	4069
	11th to 20th	Night	42% 6% 11% 27% 13% 1	3618
	21st to end	Night	30% 5% 10% 32% 22% 2	3972
June	1st to 10th	Night	22% 6% 15% 28% 22% 7%	1600
	11th to 20th	Night	25% 4 8% 19% 24% 20%	1600
	21st to end	Night	17% 5% 6% 22% 29% 21%	1600
July	1st to 10th	Night	24% 3 6% 15% 19% 33%	3600
	11th to 20th	Night	25% 3 10% 30% 20% 12%	3592
	21st to end	Night	25% 3 11% 22% 24% 15%	4227
August	1st to 10th	Night	31% 5% 16% 20% 14% 14%	2928
	11th to 20th	Night	33% 5% 12% 16% 21% 13%	3046
	21st to end	Night	26% 4 13% 18% 25% 14%	3597
September	1st to 10th	Night	22% 5% 9% 19% 27% 18%	2000
	11th to 20th	Night	26% 3 10% 23% 24% 14%	2000
	21st to end	Night	23% 4 6% 26% 32% 8%	2263
October	1st to 10th	Night	19% 3 5% 20% 40% 12%	3920
	11th to 20th	Night	29% 2 8% 36% 22% 3	3898
	21st to end	Night	34% 2 10% 33% 19% 2	4252
November	1st to 10th	Night	33% 4 11% 27% 21% 3	2625
	11th to 20th	Night	39% 5% 13% 26% 15% 2	2752
	21st to end	Night	40% 4 11% 29% 14% 2	2800
December	1st to 10th	Night	38% 3 9% 33% 16% 1	4570
	11th to 20th	Night	48% 3 14% 25% 10%	5182
	21st to end	Night	57% 5% 8% 17% 12% 1	6974

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	18% 15% 26% 27% 11% 2	300
	11th to 20th	Day	17% 14% 33% 26% 9% 1	300
	21st to end	Day	11% 16% 38% 27% 6% 2	330
February	1st to 10th	Day	24% 18% 35% 19% 4	300
	11th to 20th	Day	18% 21% 32% 24% 5%	300
	21st to end	Day	16% 24% 35% 22% 3	249
March	1st to 10th	Day	18% 23% 28% 20% 9% 1	395
	11th to 20th	Day	16% 22% 32% 24% 5% 1	500
	21st to end	Day	20% 28% 31% 18% 3	550
April	1st to 10th	Day	19% 26% 29% 19% 7%	500
	11th to 20th	Day	22% 27% 28% 17% 4 1	492
	21st to end	Day	16% 24% 31% 20% 7% 2	500
May	1st to 10th	Day	18% 20% 31% 20% 10% 1	531
	11th to 20th	Day	14% 12% 28% 29% 16% 2	725
	21st to end	Day	12% 13% 29% 28% 16% 3	789
June	1st to 10th	Day	6% 11% 28% 31% 20% 5%	730
	11th to 20th	Day	7% 14% 32% 30% 15% 2	730
	21st to end	Day	5% 8% 30% 32% 21% 3	730
July	1st to 10th	Day	5% 6% 22% 35% 29% 3	721
	11th to 20th	Day	3 5% 23% 38% 26% 6%	718
	21st to end	Day	4 5% 23% 38% 24% 5%	625
August	1st to 10th	Day	5% 7% 34% 32% 17% 5%	527
	11th to 20th	Day	4 5% 31% 33% 20% 6%	517
	21st to end	Day	5% 6% 29% 35% 19% 6%	583
September	1st to 10th	Day	6% 9% 30% 30% 18% 6%	530
	11th to 20th	Day	7% 11% 33% 28% 17% 4	530
	21st to end	Day	11% 11% 27% 25% 18% 8%	392
October	1st to 10th	Day	15% 8% 23% 29% 18% 7%	330
	11th to 20th	Day	13% 17% 28% 27% 12% 3	330
	21st to end	Day	19% 14% 33% 26% 7% 1	363
November	1st to 10th	Day	16% 19% 29% 25% 9% 2	330
	11th to 20th	Day	16% 13% 31% 31% 7% 1	321
	21st to end	Day	14% 10% 36% 31% 8% 1	300
December	1st to 10th	Day	16% 15% 32% 24% 11% 2	300
	11th to 20th	Day	16% 11% 37% 28% 7% 1	300
	21st to end	Day	20% 15% 32% 25% 7% 1	330
January	1st to 10th	Night	16% 11% 26% 35% 11% 1	1000
	11th to 20th	Night	17% 12% 30% 32% 8% 1	878
	21st to end	Night	14% 9% 33% 34% 10% 1	880
February	1st to 10th	Night	17% 10% 36% 30% 6%	800
	11th to 20th	Night	14% 11% 33% 35% 7%	784
	21st to end	Night	14% 12% 37% 33% 4	660
March	1st to 10th	Night	13% 11% 32% 35% 9% 1	800
	11th to 20th	Night	10% 8% 24% 45% 13%	800
	21st to end	Night	15% 9% 32% 35% 9% 1	814
April	1st to 10th	Night	16% 11% 29% 38% 7%	600
	11th to 20th	Night	15% 10% 31% 34% 10% 1	593
	21st to end	Night	13% 10% 25% 36% 14% 1	600
May	1st to 10th	Night	13% 6% 29% 39% 12% 1	600
	11th to 20th	Night	12% 4 21% 40% 23% 1	591
	21st to end	Night	9% 6% 23% 40% 20% 2	650
June	1st to 10th	Night	6% 4 19% 43% 27% 1	600
	11th to 20th	Night	6% 5% 24% 46% 18% 1	600
	21st to end	Night	4 3 17% 49% 26% 1	600
July	1st to 10th	Night	4 1 14% 42% 37% 3	585
	11th to 20th	Night	2 2 11% 47% 35% 3	582
	21st to end	Night	2 1 11% 43% 41% 2	657
August	1st to 10th	Night	5% 1 12% 40% 41% 1	597
	11th to 20th	Night	3 2 11% 48% 34% 2	594
	21st to end	Night	5% 1 12% 42% 36% 4	660
September	1st to 10th	Night	5% 2 12% 48% 30% 4	600
	11th to 20th	Night	6% 3 16% 43% 29% 3	600
	21st to end	Night	8% 3 18% 39% 27% 6%	727
October	1st to 10th	Night	11% 5% 22% 41% 19% 4	800
	11th to 20th	Night	12% 6% 25% 39% 17% 1	800
	21st to end	Night	15% 5% 28% 37% 13% 2	880
November	1st to 10th	Night	14% 8% 32% 32% 13% 1	985
	11th to 20th	Night	16% 9% 30% 35% 8% 1	1036
	21st to end	Night	12% 9% 27% 40% 12% 1	1000
December	1st to 10th	Night	18% 10% 31% 33% 8% 1	1000
	11th to 20th	Night	15% 11% 32% 34% 7%	1000
	21st to end	Night	20% 12% 32% 29% 7% 1	1100

Page generated at 2025-11-14 22:55:56. Version ac07

Copyright © 2025 Attilla Danko.