CSU-Pueblo Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the CSU-Pueblo Observatory clear sky chart from 2005-11-06 to 2024-02-25.

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 4 2 3 4 2 4 5% 6% 8% 58%	78540
	Night	5% 5% 2 4 3 2 4 4 5% 8% 58%	80822
Transparency	Day	21% 6% 11% 23% 25% 13%	78249
	Night	23% 6% 11% 23% 25% 12%	80635
Seeing	Day	6% 6% 22% 33% 24% 9%	14452
	Night	6% 3 25% 45% 19% 2	24649

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	3 5% 2 4 3 2 2 3 5% 10% 61%	2538
	11th to 20th	Day	1 4 2 4 4 3 4 5% 6% 8% 60%	2677
	21st to end	Day	3 6% 2 4 4 2 3 4 4 7% 59%	3146
February	1st to 10th	Day	3 6% 2 5% 4 2 4 4 5% 7% 58%	1755
	11th to 20th	Day	2 4 2 5% 4 3 4 3 6% 9% 58%	1849
	21st to end	Day	2 6% 2 6% 5% 3 4 5% 4 5% 58%	1520
March	1st to 10th	Day	1 4 2 3 4 2 4 5% 6% 8% 61%	1800
	11th to 20th	Day	6% 5% 2 3 4 2 4 4 5% 8% 57%	1934
	21st to end	Day	5% 5% 2 4 4 3 3 4 6% 8% 56%	2326
April	1st to 10th	Day	4 4 2 3 3 3 4 5% 5% 8% 59%	2160
	11th to 20th	Day	8% 6% 2 3 3 2 3 4 6% 8% 55%	2131
	21st to end	Day	7% 4 1 4 4 3 5% 4 7% 8% 53%	2160
May	1st to 10th	Day	9% 6% 1 3 4 2 4 5% 6% 9% 51%	2250
	11th to 20th	Day	7% 5% 2 4 4 3 5% 6% 8% 10% 45%	2371
	21st to end	Day	5% 3 1 3 3 3 5% 6% 7% 10% 53%	2724
June	1st to 10th	Day	4 3 1 3 4 3 5% 6% 7% 11% 52%	2520
	11th to 20th	Day	4 2 1 2 3 3 5% 5% 7% 8% 61%	2520
	21st to end	Day	3 3 2 3 4 3 6% 6% 7% 11% 53%	2520
July	1st to 10th	Day	5% 3 1 4 4 3 5% 7% 7% 9% 52%	2520
	11th to 20th	Day	2 2 1 3 4 2 4 6% 8% 12% 57%	2520
	21st to end	Day	3 3 2 4 5% 3 7% 6% 10% 12% 46%	2656
August	1st to 10th	Day	3 2 2 3 4 4 7% 7% 10% 11% 47%	2262
	11th to 20th	Day	5% 2 1 3 3 2 5% 6% 8% 10% 55%	2123
	21st to end	Day	3 3 1 3 3 2 4 5% 7% 11% 59%	2376
September	1st to 10th	Day	4 3 2 3 3 2 4 4 5% 7% 63%	2160
	11th to 20th	Day	5% 2 1 2 2 2 4 4 5% 7% 65%	2120
	21st to end	Day	5% 3 1 2 3 2 3 3 4 6% 68%	1980
October	1st to 10th	Day	7% 4 1 3 3 2 4 2 4 7% 64%	1859
	11th to 20th	Day	2 3 1 2 2 1 3 4 4 6% 72%	1800
	21st to end	Day	6% 4 1 2 3 2 2 2 4 5% 69%	1924
November	1st to 10th	Day	2 2 1 2 2 2 3 3 4 7% 72%	1673
	11th to 20th	Day	1 4 2 2 3 3 3 4 5% 5% 69%	1710
	21st to end	Day	3 5% 2 4 2 2 2 4 4 6% 65%	1710
December	1st to 10th	Day	2 4 2 4 3 2 4 5% 5% 8% 63%	1526
	11th to 20th	Day	3 4 2 4 3 2 3 3 6% 8% 62%	1926
	21st to end	Day	3 7% 2 4 4 2 5% 4 5% 6% 57%	2794
January	1st to 10th	Night	3 8% 3 5% 4 2 3 4 5% 8% 56%	4417
	11th to 20th	Night	2 4 2 4 3 2 4 5% 5% 7% 61%	4321
	21st to end	Night	3 5% 2 4 4 3 4 4 5% 7% 59%	4521
February	1st to 10th	Night	3 7% 3 5% 4 3 3 3 4 7% 58%	2423
	11th to 20th	Night	3 8% 3 5% 4 2 4 4 5% 8% 54%	2218
	21st to end	Night	3 6% 2 5% 3 2 3 4 4 6% 62%	1830
March	1st to 10th	Night	4 6% 2 3 3 2 3 4 5% 7% 61%	2160
	11th to 20th	Night	7% 6% 2 4 4 2 4 4 5% 6% 58%	2023
	21st to end	Night	5% 5% 2 5% 3 2 3 4 4 7% 59%	2029
April	1st to 10th	Night	5% 5% 1 4 3 2 3 4 5% 6% 62%	1800
	11th to 20th	Night	9% 7% 2 4 3 2 3 4 5% 8% 54%	1777
	21st to end	Night	11% 6% 2 5% 3 2 4 4 5% 8% 51%	1800
May	1st to 10th	Night	10% 6% 2 4 3 2 4 4 5% 7% 54%	1710
	11th to 20th	Night	12% 6% 3 4 4 2 4 5% 6% 9% 45%	1520
	21st to end	Night	9% 4 2 4 3 2 4 5% 5% 8% 55%	1552
June	1st to 10th	Night	5% 2 1 3 4 3 4 5% 7% 9% 57%	1440
	11th to 20th	Night	4 2 1 3 3 3 3 5% 6% 8% 62%	1440
	21st to end	Night	4 4 2 3 4 3 5% 6% 7% 10% 51%	1440
July	1st to 10th	Night	7% 2 2 4 5% 4 5% 7% 9% 10% 45%	1440
	11th to 20th	Night	3 2 1 3 5% 4 6% 5% 7% 10% 53%	1440
	21st to end	Night	6% 3 2 5% 6% 4 6% 6% 10% 11% 40%	1658
August	1st to 10th	Night	6% 4 2 5% 6% 4 7% 7% 8% 8% 44%	1677
	11th to 20th	Night	6% 4 2 3 5% 4 5% 5% 8% 10% 49%	1778
	21st to end	Night	4 4 2 4 4 3 5% 7% 7% 9% 51%	1980
September	1st to 10th	Night	5% 4 2 4 4 3 5% 4 6% 9% 54%	1800
	11th to 20th	Night	6% 2 1 3 3 2 3 5% 4 9% 63%	1840
	21st to end	Night	8% 3 1 3 2 2 3 3 4 6% 64%	1980
October	1st to 10th	Night	7% 3 1 3 3 2 3 3 4 6% 65%	2097
	11th to 20th	Night	4 3 1 2 2 1 3 3 3 5% 72%	2160
	21st to end	Night	6% 5% 1 3 2 1 2 3 4 7% 64%	2412
November	1st to 10th	Night	2 3 1 2 2 2 2 3 4 7% 71%	2405
	11th to 20th	Night	2 5% 2 3 2 1 2 3 4 5% 70%	2470
	21st to end	Night	3 5% 2 4 3 2 2 4 4 6% 64%	2470
December	1st to 10th	Night	1 5% 2 4 3 2 3 3 5% 8% 62%	2650
	11th to 20th	Night	2 5% 2 4 3 2 4 4 6% 9% 58%	3271
	21st to end	Night	5% 6% 2 5% 4 3 4 4 5% 6% 56%	4873

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	18% 5% 10% 32% 27% 8%	2539
	11th to 20th	Day	19% 5% 12% 30% 26% 9%	2677
	21st to end	Day	24% 5% 10% 29% 26% 6%	3146
February	1st to 10th	Day	24% 5% 9% 25% 24% 12%	1755
	11th to 20th	Day	22% 4 10% 25% 29% 9%	1859
	21st to end	Day	27% 5% 6% 19% 24% 19%	1520
March	1st to 10th	Day	20% 5% 11% 22% 27% 16%	1800
	11th to 20th	Day	25% 5% 9% 24% 28% 9%	1934
	21st to end	Day	25% 5% 13% 23% 23% 11%	2326
April	1st to 10th	Day	21% 5% 11% 23% 24% 16%	2160
	11th to 20th	Day	25% 6% 11% 24% 21% 14%	2134
	21st to end	Day	25% 6% 12% 23% 24% 9%	2160
May	1st to 10th	Day	29% 6% 11% 24% 22% 8%	2250
	11th to 20th	Day	29% 11% 16% 21% 18% 6%	2375
	21st to end	Day	22% 10% 16% 23% 18% 13%	2724
June	1st to 10th	Day	22% 8% 15% 24% 19% 13%	2520
	11th to 20th	Day	17% 7% 11% 17% 25% 23%	2520
	21st to end	Day	22% 7% 12% 20% 23% 16%	2520
July	1st to 10th	Day	24% 8% 13% 18% 23% 14%	2451
	11th to 20th	Day	16% 8% 14% 26% 25% 11%	2445
	21st to end	Day	25% 12% 19% 24% 16% 4	2508
August	1st to 10th	Day	24% 13% 20% 21% 13% 10%	2247
	11th to 20th	Day	21% 7% 13% 20% 25% 13%	2123
	21st to end	Day	18% 7% 13% 23% 26% 14%	2376
September	1st to 10th	Day	20% 5% 10% 22% 25% 18%	2160
	11th to 20th	Day	17% 6% 9% 18% 25% 26%	2120
	21st to end	Day	18% 4 7% 19% 33% 20%	1980
October	1st to 10th	Day	21% 6% 10% 18% 29% 16%	1859
	11th to 20th	Day	14% 3 8% 17% 33% 25%	1800
	21st to end	Day	19% 3 5% 25% 28% 19%	1924
November	1st to 10th	Day	13% 3 8% 23% 31% 22%	1673
	11th to 20th	Day	16% 4 7% 26% 33% 13%	1710
	21st to end	Day	20% 4 7% 16% 31% 22%	1710
December	1st to 10th	Day	19% 6% 12% 25% 28% 10%	1526
	11th to 20th	Day	19% 4 11% 23% 32% 11%	1924
	21st to end	Day	23% 6% 11% 23% 27% 10%	2794
January	1st to 10th	Night	24% 4 9% 29% 29% 5%	4417
	11th to 20th	Night	17% 7% 12% 29% 25% 10%	4321
	21st to end	Night	21% 7% 13% 30% 24% 4	4521
February	1st to 10th	Night	27% 4 9% 25% 25% 10%	2423
	11th to 20th	Night	27% 4 10% 27% 22% 10%	2218
	21st to end	Night	23% 3 8% 21% 31% 15%	1830
March	1st to 10th	Night	22% 4 8% 25% 26% 14%	2160
	11th to 20th	Night	25% 5% 12% 21% 27% 10%	2023
	21st to end	Night	24% 5% 10% 24% 27% 10%	2029
April	1st to 10th	Night	23% 5% 11% 22% 23% 16%	1800
	11th to 20th	Night	27% 5% 13% 23% 19% 13%	1777
	21st to end	Night	29% 5% 15% 21% 20% 9%	1800
May	1st to 10th	Night	29% 7% 12% 23% 19% 10%	1710
	11th to 20th	Night	35% 8% 16% 19% 15% 7%	1521
	21st to end	Night	28% 9% 16% 17% 16% 14%	1552
June	1st to 10th	Night	21% 8% 18% 25% 15% 13%	1440
	11th to 20th	Night	19% 6% 14% 20% 20% 22%	1440
	21st to end	Night	25% 9% 13% 19% 19% 16%	1440
July	1st to 10th	Night	31% 11% 15% 15% 20% 9%	1400
	11th to 20th	Night	22% 8% 16% 26% 20% 7%	1392
	21st to end	Night	33% 13% 17% 23% 14% 1	1566
August	1st to 10th	Night	31% 13% 19% 17% 10% 10%	1668
	11th to 20th	Night	27% 8% 15% 25% 18% 7%	1778
	21st to end	Night	24% 9% 15% 24% 19% 9%	1980
September	1st to 10th	Night	26% 5% 13% 20% 23% 13%	1800
	11th to 20th	Night	17% 6% 11% 20% 24% 23%	1840
	21st to end	Night	21% 4 8% 17% 30% 19%	1980
October	1st to 10th	Night	21% 5% 11% 19% 28% 17%	2097
	11th to 20th	Night	15% 3 7% 20% 32% 23%	2160
	21st to end	Night	20% 4 8% 20% 29% 19%	2412
November	1st to 10th	Night	14% 3 10% 24% 30% 19%	2405
	11th to 20th	Night	17% 2 6% 26% 35% 14%	2470
	21st to end	Night	21% 4 8% 20% 30% 17%	2470
December	1st to 10th	Night	21% 4 11% 28% 25% 11%	2650
	11th to 20th	Night	21% 4 10% 22% 35% 8%	3272
	21st to end	Night	25% 6% 12% 22% 27% 8%	4873

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	6% 5% 23% 40% 22% 5%	270
	11th to 20th	Day	7% 7% 26% 43% 16% 2	270
	21st to end	Day	4 4 25% 45% 15% 6%	297
February	1st to 10th	Day	4 7% 37% 37% 11% 3	270
	11th to 20th	Day	3 6% 31% 43% 15% 1	270
	21st to end	Day	4 9% 27% 50% 10%	210
March	1st to 10th	Day	2 8% 29% 38% 21% 2	240
	11th to 20th	Day	10% 8% 30% 34% 14% 3	374
	21st to end	Day	10% 17% 33% 29% 10% 1	462
April	1st to 10th	Day	6% 13% 38% 28% 13% 3	420
	11th to 20th	Day	9% 15% 37% 27% 10% 3	412
	21st to end	Day	13% 12% 29% 32% 12% 2	420
May	1st to 10th	Day	11% 10% 29% 32% 14% 3	513
	11th to 20th	Day	10% 7% 24% 32% 22% 6%	625
	21st to end	Day	6% 6% 24% 34% 23% 7%	679
June	1st to 10th	Day	5% 5% 20% 29% 31% 10%	630
	11th to 20th	Day	4 3 22% 33% 28% 9%	630
	21st to end	Day	3 5% 21% 31% 31% 10%	630
July	1st to 10th	Day	6% 3 13% 25% 39% 14%	621
	11th to 20th	Day	3 11% 24% 41% 19%	618
	21st to end	Day	3 2 8% 24% 39% 25%	598
August	1st to 10th	Day	3 1 15% 30% 34% 18%	447
	11th to 20th	Day	3 3 15% 32% 27% 19%	437
	21st to end	Day	3 3 10% 35% 33% 16%	495
September	1st to 10th	Day	6% 2 18% 32% 27% 16%	450
	11th to 20th	Day	5% 2 18% 32% 30% 12%	410
	21st to end	Day	7% 3 11% 26% 34% 18%	270
October	1st to 10th	Day	9% 2 20% 27% 21% 20%	270
	11th to 20th	Day	2 5% 17% 36% 27% 13%	270
	21st to end	Day	8% 5% 17% 35% 27% 8%	297
November	1st to 10th	Day	2 4 20% 42% 25% 7%	270
	11th to 20th	Day	4 4 22% 40% 21% 8%	270
	21st to end	Day	9% 5% 17% 40% 24% 6%	270
December	1st to 10th	Day	2 6% 27% 42% 15% 7%	270
	11th to 20th	Day	5% 4 24% 46% 18% 3	270
	21st to end	Day	4 5% 35% 41% 13% 2	297
January	1st to 10th	Night	4 4 27% 48% 14% 2	950
	11th to 20th	Night	5% 2 35% 43% 13% 1	880
	21st to end	Night	5% 1 28% 51% 14% 1	836
February	1st to 10th	Night	5% 3 35% 48% 9% 1	760
	11th to 20th	Night	5% 4 35% 45% 10%	744
	21st to end	Night	7% 3 41% 43% 5%	610
March	1st to 10th	Night	5% 5% 34% 47% 8% 1	720
	11th to 20th	Night	9% 4 27% 46% 13% 1	720
	21st to end	Night	7% 6% 35% 46% 6%	643
April	1st to 10th	Night	7% 6% 41% 38% 7%	540
	11th to 20th	Night	12% 8% 31% 38% 10%	533
	21st to end	Night	11% 6% 29% 42% 11% 1	540
May	1st to 10th	Night	10% 5% 31% 42% 12%	540
	11th to 20th	Night	13% 4 21% 40% 20% 2	531
	21st to end	Night	9% 4 28% 40% 17% 1	584
June	1st to 10th	Night	4 2 23% 44% 24% 2	540
	11th to 20th	Night	5% 2 23% 51% 18% 1	540
	21st to end	Night	4 3 18% 47% 28% 1	540
July	1st to 10th	Night	8% 2 12% 39% 37% 2	525
	11th to 20th	Night	4 1 9% 42% 39% 5%	522
	21st to end	Night	7% 2 7% 32% 48% 4	591
August	1st to 10th	Night	8% 1 7% 38% 43% 2	537
	11th to 20th	Night	6% 2 11% 43% 36% 2	534
	21st to end	Night	4 2 8% 42% 42% 3	594
September	1st to 10th	Night	6% 2 10% 45% 33% 4	540
	11th to 20th	Night	6% 2 13% 45% 30% 4	540
	21st to end	Night	8% 4 16% 45% 25% 2	540
October	1st to 10th	Night	10% 2 22% 44% 21% 2	657
	11th to 20th	Night	5% 2 21% 45% 24% 3	720
	21st to end	Night	7% 3 23% 43% 22% 2	828
November	1st to 10th	Night	3 2 23% 53% 18% 1	925
	11th to 20th	Night	4 4 26% 49% 15% 2	950
	21st to end	Night	6% 4 27% 43% 18% 1	950
December	1st to 10th	Night	4 2 30% 49% 13% 1	950
	11th to 20th	Night	5% 3 30% 49% 12% 1	950
	21st to end	Night	6% 4 33% 48% 9%	1045

Page generated at 2024-02-22 04:05:44. Version ac07

Copyright 2024 Attilla Danko