Red Feather Lakes
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Red Feather Lakes clear sky chart from 2005-11-06 to 2025-04-26.

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	3 5% 2 6% 4 4 5% 4 6% 8% 52%	117682
	Night	2 5% 2 5% 3 3 3 3 5% 8% 61%	119805
Transparency	Day	27% 6% 11% 24% 22% 9%	117427
	Night	22% 5% 12% 28% 25% 8%	119651
Seeing	Day	18% 25% 31% 18% 7% 2	16222
	Night	16% 27% 26% 21% 8% 1	26398

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 2 8% 4 3 4 3 5% 9% 58%	3638
	11th to 20th	Day	2 1 5% 5% 5% 5% 4 6% 11% 54%	3714
	21st to end	Day	4 3 7% 3 3 4 3 5% 7% 61%	4510
February	1st to 10th	Day	5% 3 7% 5% 3 4 4 7% 8% 54%	1800
	11th to 20th	Day	4 3 6% 5% 3 5% 4 7% 10% 54%	1867
	21st to end	Day	6% 3 6% 3 4 4 3 6% 8% 57%	1650
March	1st to 10th	Day	1 6% 4 8% 4 3 4 3 6% 8% 53%	4500
	11th to 20th	Day	1 9% 3 7% 4 5% 6% 5% 8% 8% 44%	5000
	21st to end	Day	2 7% 2 5% 4 4 5% 5% 8% 10% 50%	5780
April	1st to 10th	Day	3 7% 3 6% 4 4 4 4 7% 8% 50%	2400
	11th to 20th	Day	7% 10% 4 8% 4 4 5% 3 8% 8% 41%	2371
	21st to end	Day	6% 10% 3 8% 6% 5% 5% 5% 7% 8% 37%	2341
May	1st to 10th	Day	7% 13% 3 7% 5% 5% 5% 4 7% 8% 36%	4135
	11th to 20th	Day	7% 8% 3 6% 5% 6% 6% 5% 7% 9% 40%	4388
	21st to end	Day	4 5% 1 5% 4 5% 6% 6% 9% 9% 45%	4825
June	1st to 10th	Day	4 4 2 4 4 6% 6% 7% 8% 9% 45%	2660
	11th to 20th	Day	6% 4 2 5% 3 5% 5% 5% 6% 8% 52%	2660
	21st to end	Day	2 4 2 5% 5% 5% 5% 5% 7% 9% 50%	2660
July	1st to 10th	Day	4 3 2 5% 4 5% 6% 5% 7% 7% 52%	4430
	11th to 20th	Day	2 3 2 6% 6% 7% 7% 6% 8% 9% 46%	4430
	21st to end	Day	4 4 2 6% 4 5% 5% 5% 7% 9% 48%	4740
August	1st to 10th	Day	5% 6% 2 6% 5% 6% 6% 6% 8% 10% 39%	4092
	11th to 20th	Day	3 4 2 7% 4 5% 6% 5% 7% 9% 49%	3818
	21st to end	Day	4 4 2 5% 5% 4 5% 4 6% 8% 52%	4180
September	1st to 10th	Day	5% 5% 2 4 4 4 4 3 5% 6% 58%	2280
	11th to 20th	Day	6% 3 2 5% 3 4 4 4 5% 7% 56%	2280
	21st to end	Day	6% 6% 2 4 2 3 2 2 4 6% 62%	2066
October	1st to 10th	Day	3 4 1 3 2 2 3 2 3 5% 72%	3170
	11th to 20th	Day	4 4 1 5% 4 4 4 3 6% 8% 57%	3150
	21st to end	Day	3 7% 2 4 3 3 4 3 5% 6% 62%	3324
November	1st to 10th	Day	2 5% 2 3 4 2 4 3 6% 7% 64%	1763
	11th to 20th	Day	1 4 2 3 2 3 3 3 5% 9% 64%	1800
	21st to end	Day	4 2 5% 5% 4 5% 3 5% 8% 59%	1610
December	1st to 10th	Day	2 1 3 2 2 2 3 4 7% 72%	2620
	11th to 20th	Day	1 4 2 4 3 2 3 3 6% 9% 64%	3026
	21st to end	Day	1 5% 3 8% 4 4 4 3 6% 9% 53%	4004
January	1st to 10th	Night	3 3 7% 4 3 4 4 6% 8% 57%	6327
	11th to 20th	Night	1 1 4 4 4 3 3 5% 8% 65%	6294
	21st to end	Night	4 2 6% 3 3 3 3 4 8% 65%	6468
February	1st to 10th	Night	4 2 6% 3 4 4 3 6% 9% 60%	2600
	11th to 20th	Night	4 2 6% 4 3 4 3 6% 8% 60%	2419
	21st to end	Night	6% 3 5% 3 4 3 3 4 7% 61%	1980
March	1st to 10th	Night	6% 4 8% 4 3 3 3 5% 6% 57%	5358
	11th to 20th	Night	1 8% 3 6% 3 3 3 3 5% 7% 58%	5000
	21st to end	Night	3 7% 2 6% 4 3 3 3 6% 9% 54%	5180
April	1st to 10th	Night	2 6% 2 4 5% 4 4 3 6% 7% 56%	2000
	11th to 20th	Night	5% 8% 3 7% 3 3 3 4 5% 8% 52%	1977
	21st to end	Night	8% 10% 2 5% 3 3 3 3 6% 8% 49%	1955
May	1st to 10th	Night	6% 9% 2 5% 4 5% 5% 3 5% 7% 50%	2815
	11th to 20th	Night	7% 8% 2 4 4 3 4 4 6% 8% 50%	2517
	21st to end	Night	4 5% 2 4 3 4 4 3 7% 8% 57%	2762
June	1st to 10th	Night	3 3 1 3 2 3 4 4 7% 9% 59%	1520
	11th to 20th	Night	4 3 1 3 2 3 5% 4 5% 8% 61%	1520
	21st to end	Night	4 3 2 3 2 3 3 4 6% 8% 62%	1520
July	1st to 10th	Night	3 3 1 4 3 4 3 3 5% 7% 62%	2540
	11th to 20th	Night	1 3 1 3 3 3 5% 4 7% 11% 58%	2540
	21st to end	Night	2 3 2 4 3 4 4 4 7% 7% 60%	2819
August	1st to 10th	Night	5% 7% 1 4 3 3 4 4 7% 11% 50%	2847
	11th to 20th	Night	2 3 2 5% 4 4 5% 4 7% 9% 54%	3021
	21st to end	Night	3 3 1 3 4 4 4 3 7% 9% 59%	3487
September	1st to 10th	Night	5% 4 1 4 3 3 4 3 4 7% 61%	1900
	11th to 20th	Night	6% 3 1 3 2 3 3 2 5% 7% 65%	1900
	21st to end	Night	5% 3 1 3 3 3 3 3 4 7% 65%	2112
October	1st to 10th	Night	3 4 1 3 2 2 2 2 4 5% 74%	3800
	11th to 20th	Night	3 5% 2 4 3 3 3 3 6% 8% 60%	3778
	21st to end	Night	2 5% 2 5% 3 3 2 2 4 7% 65%	4203
November	1st to 10th	Night	2 3 1 3 3 3 3 3 5% 7% 67%	2535
	11th to 20th	Night	1 4 2 3 3 2 2 3 5% 8% 67%	2600
	21st to end	Night	1 4 2 5% 3 3 3 4 5% 7% 61%	2786
December	1st to 10th	Night	2 1 3 1 2 2 2 4 7% 75%	4570
	11th to 20th	Night	1 4 2 4 2 2 2 3 5% 8% 67%	5181
	21st to end	Night	1 5% 2 6% 4 3 4 3 6% 9% 57%	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	23% 4 14% 29% 25% 5%	3639
	11th to 20th	Day	21% 6% 17% 21% 29% 6%	3714
	21st to end	Day	20% 6% 12% 27% 25% 10%	4510
February	1st to 10th	Day	26% 7% 18% 25% 19% 6%	1800
	11th to 20th	Day	24% 6% 16% 29% 21% 5%	1876
	21st to end	Day	24% 5% 13% 26% 25% 7%	1650
March	1st to 10th	Day	29% 4 7% 22% 29% 8%	4500
	11th to 20th	Day	31% 7% 11% 26% 21% 3	5000
	21st to end	Day	25% 7% 15% 38% 14% 1	5780
April	1st to 10th	Day	29% 6% 14% 26% 18% 7%	2400
	11th to 20th	Day	38% 4 13% 23% 17% 5%	2374
	21st to end	Day	40% 7% 10% 27% 14% 1	2341
May	1st to 10th	Day	41% 7% 10% 20% 17% 5%	4135
	11th to 20th	Day	36% 11% 11% 25% 15% 3	4392
	21st to end	Day	27% 7% 11% 25% 24% 5%	4825
June	1st to 10th	Day	29% 10% 18% 21% 16% 6%	2660
	11th to 20th	Day	28% 7% 10% 19% 24% 12%	2660
	21st to end	Day	26% 8% 11% 21% 23% 12%	2660
July	1st to 10th	Day	26% 6% 11% 13% 22% 22%	4361
	11th to 20th	Day	28% 8% 10% 19% 19% 16%	4355
	21st to end	Day	29% 7% 10% 17% 19% 19%	4591
August	1st to 10th	Day	33% 11% 14% 18% 15% 8%	4078
	11th to 20th	Day	28% 8% 12% 16% 21% 15%	3856
	21st to end	Day	27% 6% 11% 17% 25% 14%	4179
September	1st to 10th	Day	25% 6% 9% 18% 27% 14%	2280
	11th to 20th	Day	26% 6% 9% 21% 26% 12%	2280
	21st to end	Day	24% 4 8% 21% 34% 9%	2066
October	1st to 10th	Day	17% 4 5% 16% 35% 22%	3170
	11th to 20th	Day	24% 5% 9% 33% 25% 5%	3150
	21st to end	Day	23% 4 7% 30% 30% 6%	3324
November	1st to 10th	Day	19% 4 14% 28% 30% 6%	1763
	11th to 20th	Day	18% 5% 14% 30% 26% 8%	1800
	21st to end	Day	23% 5% 13% 30% 21% 9%	1610
December	1st to 10th	Day	13% 4 12% 35% 29% 6%	2620
	11th to 20th	Day	17% 5% 13% 36% 26% 2	3024
	21st to end	Day	26% 6% 10% 29% 20% 9%	4004
January	1st to 10th	Night	23% 4 12% 30% 23% 8%	6327
	11th to 20th	Night	18% 3 16% 26% 27% 10%	6294
	21st to end	Night	20% 5% 12% 26% 28% 11%	6468
February	1st to 10th	Night	21% 6% 20% 27% 21% 6%	2600
	11th to 20th	Night	22% 5% 15% 32% 22% 4	2420
	21st to end	Night	23% 3 12% 28% 25% 9%	1980
March	1st to 10th	Night	28% 4 7% 21% 30% 10%	5358
	11th to 20th	Night	25% 4 10% 22% 31% 8%	5000
	21st to end	Night	26% 6% 16% 35% 16% 1	5180
April	1st to 10th	Night	25% 6% 13% 29% 20% 7%	2000
	11th to 20th	Night	30% 5% 14% 29% 18% 4	1977
	21st to end	Night	32% 6% 10% 32% 19% 1	1955
May	1st to 10th	Night	32% 7% 9% 25% 21% 6%	2815
	11th to 20th	Night	29% 10% 13% 31% 15% 2	2518
	21st to end	Night	23% 6% 13% 27% 27% 4	2762
June	1st to 10th	Night	19% 9% 22% 28% 17% 6%	1520
	11th to 20th	Night	19% 7% 12% 24% 24% 14%	1520
	21st to end	Night	18% 7% 10% 25% 25% 15%	1520
July	1st to 10th	Night	20% 5% 10% 21% 24% 20%	2500
	11th to 20th	Night	19% 5% 13% 28% 22% 13%	2492
	21st to end	Night	21% 5% 12% 26% 19% 17%	2731
August	1st to 10th	Night	26% 7% 18% 23% 19% 7%	2838
	11th to 20th	Night	23% 7% 19% 20% 20% 11%	3049
	21st to end	Night	20% 5% 13% 23% 30% 8%	3487
September	1st to 10th	Night	22% 5% 10% 21% 27% 16%	1900
	11th to 20th	Night	20% 4 9% 27% 26% 14%	1900
	21st to end	Night	21% 4 8% 27% 31% 9%	2112
October	1st to 10th	Night	15% 3 6% 23% 34% 19%	3800
	11th to 20th	Night	22% 5% 9% 34% 24% 7%	3778
	21st to end	Night	20% 3 9% 30% 30% 8%	4203
November	1st to 10th	Night	18% 5% 15% 27% 28% 8%	2535
	11th to 20th	Night	17% 4 15% 30% 27% 7%	2600
	21st to end	Night	21% 5% 11% 30% 26% 7%	2786
December	1st to 10th	Night	11% 4 13% 37% 30% 6%	4570
	11th to 20th	Night	16% 5% 10% 36% 28% 3	5182
	21st to end	Night	23% 7% 12% 25% 26% 7%	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	28% 32% 24% 9% 5% 2	300
	11th to 20th	Day	30% 38% 19% 11% 1	300
	21st to end	Day	27% 41% 23% 6% 3	330
February	1st to 10th	Day	42% 36% 17% 4 1 1	300
	11th to 20th	Day	37% 34% 24% 4 2	300
	21st to end	Day	35% 40% 20% 5%	249
March	1st to 10th	Day	26% 34% 28% 10% 1	300
	11th to 20th	Day	24% 33% 30% 10% 3	500
	21st to end	Day	24% 36% 30% 8% 2	550
April	1st to 10th	Day	27% 34% 28% 9% 1	500
	11th to 20th	Day	30% 35% 28% 6% 1	492
	21st to end	Day	22% 33% 29% 12% 3 1	481
May	1st to 10th	Day	22% 32% 26% 13% 5% 1	583
	11th to 20th	Day	19% 17% 35% 17% 8% 2	675
	21st to end	Day	14% 21% 30% 25% 9% 1	734
June	1st to 10th	Day	8% 18% 32% 26% 13% 3	680
	11th to 20th	Day	11% 20% 40% 19% 7% 2	680
	21st to end	Day	7% 17% 37% 24% 13% 3	680
July	1st to 10th	Day	8% 7% 31% 34% 18% 3	671
	11th to 20th	Day	4 9% 36% 32% 15% 4	668
	21st to end	Day	6% 7% 33% 32% 18% 4	701
August	1st to 10th	Day	9% 11% 40% 31% 7% 2	487
	11th to 20th	Day	6% 11% 40% 29% 12% 2	477
	21st to end	Day	7% 14% 36% 33% 8% 2	539
September	1st to 10th	Day	8% 17% 37% 27% 10% 2	490
	11th to 20th	Day	10% 20% 39% 22% 8% 1	490
	21st to end	Day	14% 20% 32% 20% 10% 3	305
October	1st to 10th	Day	13% 22% 30% 23% 10% 3	300
	11th to 20th	Day	22% 31% 27% 13% 5% 2	300
	21st to end	Day	19% 38% 28% 11% 3	330
November	1st to 10th	Day	26% 32% 26% 10% 6% 1	300
	11th to 20th	Day	27% 39% 23% 9% 2	300
	21st to end	Day	22% 41% 28% 8% 1	300
December	1st to 10th	Day	32% 34% 25% 6% 2	300
	11th to 20th	Day	33% 42% 20% 5% 1	300
	21st to end	Day	36% 32% 21% 9% 1 1	330
January	1st to 10th	Night	25% 38% 20% 13% 3 1	1000
	11th to 20th	Night	28% 42% 17% 8% 4 1	980
	21st to end	Night	21% 43% 24% 9% 3	880
February	1st to 10th	Night	27% 40% 21% 9% 2	800
	11th to 20th	Night	22% 37% 27% 13% 1	784
	21st to end	Night	27% 41% 23% 8% 1	660
March	1st to 10th	Night	18% 37% 30% 12% 4	800
	11th to 20th	Night	17% 31% 28% 19% 4 1	800
	21st to end	Night	15% 34% 31% 15% 3 1	752
April	1st to 10th	Night	15% 32% 36% 16% 2	600
	11th to 20th	Night	16% 30% 32% 15% 6%	593
	21st to end	Night	17% 25% 28% 23% 6% 1	587
May	1st to 10th	Night	15% 19% 36% 20% 8% 1	570
	11th to 20th	Night	17% 11% 29% 29% 13% 1	561
	21st to end	Night	12% 12% 31% 28% 17% 2	617
June	1st to 10th	Night	6% 9% 31% 36% 17% 2	570
	11th to 20th	Night	7% 14% 37% 31% 11%	570
	21st to end	Night	5% 7% 30% 36% 20% 1	570
July	1st to 10th	Night	6% 3 19% 43% 26% 3	555
	11th to 20th	Night	2 3 25% 42% 24% 3	552
	21st to end	Night	5% 3 16% 46% 27% 3	624
August	1st to 10th	Night	7% 4 19% 48% 21% 2	567
	11th to 20th	Night	4 5% 25% 42% 22% 3	564
	21st to end	Night	4 6% 21% 42% 23% 4	627
September	1st to 10th	Night	8% 6% 23% 40% 18% 4	570
	11th to 20th	Night	8% 9% 28% 37% 16% 2	570
	21st to end	Night	8% 16% 27% 33% 14% 2	597
October	1st to 10th	Night	11% 20% 31% 26% 10% 2	760
	11th to 20th	Night	17% 29% 26% 21% 7% 1	760
	21st to end	Night	15% 34% 33% 12% 5% 1	883
November	1st to 10th	Night	15% 36% 30% 14% 4 1	975
	11th to 20th	Night	25% 37% 26% 10% 2 1	1000
	21st to end	Night	17% 39% 29% 11% 3	1000
December	1st to 10th	Night	27% 38% 24% 10% 2	1000
	11th to 20th	Night	23% 45% 19% 10% 3 1	1000
	21st to end	Night	28% 39% 21% 9% 3	1100

Page generated at 2025-04-23 07:25:07. Version ac07

Copyright © 2025 Attilla Danko.