Chamberlain Creek Rest Stop
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chamberlain Creek Rest Stop clear sky chart from 2005-11-06 to 2024-12-09.

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	11% 6% 2 4 3 3 3 3 4 6% 56%	105408
	Night	13% 7% 2 6% 3 3 3 3 4 5% 50%	103122
Transparency	Day	29% 5% 10% 20% 21% 16%	105169
	Night	35% 5% 11% 17% 18% 14%	102951
Seeing	Day	16% 10% 25% 27% 15% 5%	15431
	Night	16% 5% 13% 28% 29% 8%	24639

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	25% 10% 2 6% 4 3 3 3 4 6% 32%	2735
	11th to 20th	Day	32% 10% 3 8% 4 3 3 2 4 5% 28%	2860
	21st to end	Day	30% 9% 3 6% 4 4 4 2 5% 6% 27%	3146
February	1st to 10th	Day	22% 8% 2 6% 4 4 3 3 3 6% 41%	1710
	11th to 20th	Day	19% 9% 2 5% 3 3 4 3 5% 6% 39%	1665
	21st to end	Day	20% 9% 2 5% 4 3 3 3 5% 7% 38%	1576
March	1st to 10th	Day	31% 16% 3 6% 3 3 2 2 3 4 27%	3442
	11th to 20th	Day	15% 6% 2 6% 3 3 3 2 4 6% 49%	3490
	21st to end	Day	24% 10% 3 6% 4 4 5% 4 5% 7% 28%	3825
April	1st to 10th	Day	18% 9% 2 6% 4 4 4 4 6% 7% 35%	2254
	11th to 20th	Day	16% 8% 2 5% 3 3 4 3 5% 6% 44%	2249
	21st to end	Day	10% 6% 1 5% 4 3 4 3 5% 9% 50%	2339
May	1st to 10th	Day	7% 5% 1 3 2 3 3 3 4 6% 63%	4110
	11th to 20th	Day	6% 3 1 3 2 2 2 2 3 5% 71%	4100
	21st to end	Day	5% 5% 1 3 2 2 2 2 3 6% 67%	4813
June	1st to 10th	Day	8% 6% 2 5% 4 3 3 4 5% 7% 52%	2660
	11th to 20th	Day	3 3 1 3 2 2 3 3 4 7% 70%	2660
	21st to end	Day	4 3 1 4 2 2 3 2 3 6% 71%	2660
July	1st to 10th	Day	1 2 2 1 1 1 1 2 3 85%	4399
	11th to 20th	Day	2 1 1 3 2 2 2 2 3 5% 77%	4110
	21st to end	Day	2 1 3 2 1 2 2 3 5% 80%	4455
August	1st to 10th	Day	1 2 1 4 3 2 3 3 4 7% 70%	4091
	11th to 20th	Day	2 2 1 3 2 1 2 2 3 4 78%	4026
	21st to end	Day	2 2 1 3 2 2 2 2 3 5% 74%	4180
September	1st to 10th	Day	2 2 1 2 2 2 2 2 3 6% 77%	2280
	11th to 20th	Day	4 4 2 4 2 3 3 3 4 6% 64%	2204
	21st to end	Day	4 3 1 2 1 2 3 2 3 6% 73%	2040
October	1st to 10th	Day	5% 3 2 2 2 3 2 4 4 73%	3180
	11th to 20th	Day	9% 4 2 4 2 3 4 3 5% 7% 57%	3161
	21st to end	Day	11% 6% 2 6% 3 3 4 3 5% 7% 49%	3448
November	1st to 10th	Day	14% 5% 2 5% 4 3 4 4 5% 8% 46%	1959
	11th to 20th	Day	18% 7% 2 6% 4 4 3 2 5% 7% 41%	1675
	21st to end	Day	14% 5% 2 5% 4 3 5% 4 5% 7% 47%	1600
December	1st to 10th	Day	18% 9% 3 5% 3 3 4 3 5% 7% 41%	1584
	11th to 20th	Day	31% 10% 3 6% 4 4 4 3 4 5% 26%	1928
	21st to end	Day	25% 10% 4 7% 6% 3 3 3 4 6% 28%	2794
January	1st to 10th	Night	22% 10% 2 6% 4 4 4 3 5% 7% 32%	4213
	11th to 20th	Night	27% 13% 4 8% 4 3 3 3 4 5% 26%	4110
	21st to end	Night	33% 11% 3 7% 4 3 3 2 4 5% 25%	4521
February	1st to 10th	Night	19% 7% 3 6% 4 4 4 4 4 5% 41%	2470
	11th to 20th	Night	17% 10% 4 8% 4 4 4 3 5% 5% 35%	2402
	21st to end	Night	18% 8% 2 5% 3 3 3 3 5% 5% 45%	1875
March	1st to 10th	Night	28% 19% 3 5% 3 2 3 2 3 4 27%	3432
	11th to 20th	Night	17% 6% 2 8% 4 3 2 2 4 5% 46%	3490
	21st to end	Night	20% 16% 3 7% 4 3 5% 3 5% 5% 29%	3828
April	1st to 10th	Night	16% 10% 3 6% 4 3 3 3 5% 7% 38%	1925
	11th to 20th	Night	13% 9% 2 6% 3 3 3 3 5% 7% 46%	1879
	21st to end	Night	8% 5% 2 5% 4 3 3 3 6% 8% 53%	1838
May	1st to 10th	Night	9% 5% 1 4 2 2 2 1 3 5% 66%	2860
	11th to 20th	Night	3 4 2 7% 3 3 2 2 2 4 67%	2788
	21st to end	Night	4 4 2 4 3 2 2 2 3 5% 69%	2762
June	1st to 10th	Night	6% 7% 3 6% 3 3 4 3 4 7% 53%	1520
	11th to 20th	Night	3 2 2 3 2 2 2 3 3 6% 73%	1520
	21st to end	Night	4 3 1 4 2 4 3 2 4 3 70%	1520
July	1st to 10th	Night	1 1 2 2 1 1 1 2 3 85%	2558
	11th to 20th	Night	1 1 2 7% 4 3 2 2 3 5% 70%	2860
	21st to end	Night	1 3 5% 4 4 3 2 4 6% 69%	3109
August	1st to 10th	Night	1 2 2 8% 6% 4 4 3 4 6% 58%	2848
	11th to 20th	Night	4 1 6% 3 2 3 3 3 4 70%	2812
	21st to end	Night	4 3 1 4 3 3 2 1 3 3 73%	3497
September	1st to 10th	Night	1 3 1 2 3 1 1 1 4 6% 76%	1900
	11th to 20th	Night	5% 7% 3 5% 3 3 4 2 4 7% 59%	1972
	21st to end	Night	4 5% 2 4 2 2 2 3 5% 5% 66%	2139
October	1st to 10th	Night	4 3 1 4 3 2 2 2 3 4 75%	3800
	11th to 20th	Night	8% 11% 3 7% 3 3 3 2 3 6% 51%	3777
	21st to end	Night	11% 4 2 5% 4 4 4 3 5% 7% 50%	4121
November	1st to 10th	Night	14% 7% 2 6% 4 4 5% 4 6% 6% 42%	2340
	11th to 20th	Night	17% 8% 2 7% 4 4 4 4 6% 7% 38%	2720
	21st to end	Night	16% 6% 1 5% 3 3 4 3 5% 7% 46%	2800
December	1st to 10th	Night	20% 7% 2 6% 4 4 4 3 4 7% 39%	2778
	11th to 20th	Night	34% 9% 2 5% 3 3 3 3 4 6% 28%	3276
	21st to end	Night	25% 10% 3 7% 4 4 4 3 4 6% 31%	4862

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	51% 8% 15% 18% 6% 3	2735
	11th to 20th	Day	60% 5% 11% 8% 8% 8%	2860
	21st to end	Day	57% 5% 8% 14% 10% 5%	3146
February	1st to 10th	Day	46% 4 8% 16% 18% 7%	1710
	11th to 20th	Day	45% 6% 7% 19% 19% 4	1674
	21st to end	Day	46% 4 14% 19% 13% 4	1576
March	1st to 10th	Day	61% 5% 7% 16% 9% 1	3442
	11th to 20th	Day	36% 6% 12% 21% 17% 8%	3490
	21st to end	Day	53% 9% 13% 16% 7% 1	3825
April	1st to 10th	Day	46% 7% 12% 22% 12% 1	2254
	11th to 20th	Day	40% 6% 15% 23% 13% 3	2252
	21st to end	Day	30% 7% 15% 28% 16% 3	2339
May	1st to 10th	Day	21% 9% 15% 27% 19% 9%	4110
	11th to 20th	Day	17% 4 7% 26% 38% 8%	4103
	21st to end	Day	19% 5% 13% 47% 15%	4814
June	1st to 10th	Day	29% 8% 11% 27% 21% 4	2660
	11th to 20th	Day	15% 4 11% 27% 34% 9%	2660
	21st to end	Day	16% 3 7% 20% 37% 17%	2660
July	1st to 10th	Day	7% 2 4 8% 19% 61%	4330
	11th to 20th	Day	10% 2 7% 11% 22% 48%	4041
	21st to end	Day	8% 2 6% 9% 36% 39%	4315
August	1st to 10th	Day	12% 2 9% 13% 30% 34%	4076
	11th to 20th	Day	10% 3 6% 22% 38% 21%	4065
	21st to end	Day	13% 2 9% 23% 28% 26%	4179
September	1st to 10th	Day	9% 2 7% 14% 31% 37%	2280
	11th to 20th	Day	20% 3 10% 27% 31% 9%	2204
	21st to end	Day	14% 3 7% 22% 30% 23%	2040
October	1st to 10th	Day	17% 2 4 18% 18% 41%	3180
	11th to 20th	Day	25% 5% 8% 24% 29% 10%	3161
	21st to end	Day	34% 5% 9% 23% 19% 10%	3448
November	1st to 10th	Day	36% 6% 10% 24% 15% 9%	1959
	11th to 20th	Day	43% 5% 13% 18% 14% 8%	1675
	21st to end	Day	35% 7% 11% 16% 21% 11%	1600
December	1st to 10th	Day	43% 5% 10% 16% 16% 11%	1584
	11th to 20th	Day	60% 5% 8% 11% 12% 3	1928
	21st to end	Day	55% 8% 10% 17% 9% 3	2794
January	1st to 10th	Night	50% 9% 19% 13% 7% 3	4213
	11th to 20th	Night	61% 7% 8% 11% 6% 7%	4110
	21st to end	Night	62% 6% 7% 11% 10% 5%	4521
February	1st to 10th	Night	44% 6% 9% 17% 17% 7%	2470
	11th to 20th	Night	50% 6% 8% 17% 15% 5%	2404
	21st to end	Night	40% 5% 16% 22% 14% 3	1875
March	1st to 10th	Night	60% 7% 8% 14% 9% 1	3432
	11th to 20th	Night	37% 8% 13% 19% 14% 9%	3490
	21st to end	Night	53% 9% 14% 15% 7% 2	3828
April	1st to 10th	Night	45% 6% 14% 20% 11% 3	1925
	11th to 20th	Night	37% 6% 15% 24% 14% 3	1879
	21st to end	Night	29% 5% 17% 31% 16% 3	1838
May	1st to 10th	Night	21% 6% 13% 27% 22% 12%	2860
	11th to 20th	Night	19% 5% 10% 17% 37% 13%	2789
	21st to end	Night	18% 5% 12% 46% 18% 1	2762
June	1st to 10th	Night	30% 7% 11% 28% 20% 4	1520
	11th to 20th	Night	13% 5% 8% 26% 37% 10%	1520
	21st to end	Night	16% 3 11% 16% 35% 20%	1520
July	1st to 10th	Night	6% 1 5% 8% 17% 62%	2518
	11th to 20th	Night	13% 1 10% 9% 20% 47%	2806
	21st to end	Night	12% 2 12% 6% 30% 38%	3011
August	1st to 10th	Night	16% 2 18% 12% 26% 27%	2839
	11th to 20th	Night	15% 2 11% 18% 31% 21%	2839
	21st to end	Night	14% 2 9% 19% 26% 29%	3497
September	1st to 10th	Night	10% 1 7% 14% 29% 38%	1900
	11th to 20th	Night	24% 3 11% 20% 32% 9%	1972
	21st to end	Night	18% 4 10% 18% 26% 24%	2139
October	1st to 10th	Night	16% 2 6% 14% 21% 42%	3800
	11th to 20th	Night	34% 5% 8% 15% 28% 9%	3777
	21st to end	Night	33% 4 9% 24% 18% 12%	4121
November	1st to 10th	Night	40% 7% 14% 17% 15% 8%	2340
	11th to 20th	Night	43% 7% 13% 17% 15% 5%	2720
	21st to end	Night	37% 5% 11% 17% 18% 11%	2800
December	1st to 10th	Night	45% 5% 10% 16% 16% 8%	2778
	11th to 20th	Night	59% 4 8% 14% 12% 4	3276
	21st to end	Night	55% 7% 11% 17% 8% 3	4862

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	39% 10% 22% 17% 10% 1	298
	11th to 20th	Day	31% 11% 22% 22% 12% 4	370
	21st to end	Day	27% 10% 23% 21% 14% 4	407
February	1st to 10th	Day	26% 13% 20% 23% 14% 3	370
	11th to 20th	Day	30% 15% 23% 18% 13% 1	365
	21st to end	Day	25% 15% 26% 23% 10% 2	368
March	1st to 10th	Day	36% 17% 25% 16% 5% 1	460
	11th to 20th	Day	27% 15% 29% 18% 8% 2	460
	21st to end	Day	29% 17% 28% 17% 7% 2	506
April	1st to 10th	Day	25% 18% 30% 17% 8% 2	460
	11th to 20th	Day	26% 15% 29% 20% 8% 3	452
	21st to end	Day	17% 20% 31% 20% 9% 5%	460
May	1st to 10th	Day	17% 16% 28% 26% 10% 3	463
	11th to 20th	Day	19% 15% 27% 22% 11% 6%	488
	21st to end	Day	18% 13% 28% 25% 12% 5%	529
June	1st to 10th	Day	14% 11% 30% 28% 12% 4	490
	11th to 20th	Day	9% 17% 33% 27% 11% 4	490
	21st to end	Day	4 7% 28% 36% 18% 7%	490
July	1st to 10th	Day	6% 3 26% 42% 15% 7%	486
	11th to 20th	Day	3 2 25% 40% 21% 9%	484
	21st to end	Day	2 2 19% 44% 24% 9%	531
August	1st to 10th	Day	3 4 28% 38% 18% 8%	487
	11th to 20th	Day	4 5% 24% 36% 23% 8%	477
	21st to end	Day	4 4 25% 38% 21% 8%	539
September	1st to 10th	Day	4 6% 24% 37% 21% 8%	490
	11th to 20th	Day	7% 8% 25% 35% 19% 6%	490
	21st to end	Day	8% 7% 24% 32% 21% 8%	490
October	1st to 10th	Day	9% 9% 24% 26% 24% 7%	490
	11th to 20th	Day	14% 8% 17% 28% 22% 11%	490
	21st to end	Day	16% 9% 21% 31% 17% 6%	539
November	1st to 10th	Day	17% 10% 25% 23% 20% 5%	495
	11th to 20th	Day	19% 9% 17% 23% 23% 9%	243
	21st to end	Day	19% 6% 25% 21% 23% 8%	200
December	1st to 10th	Day	25% 11% 16% 22% 14% 11%	196
	11th to 20th	Day	29% 13% 18% 19% 12% 8%	180
	21st to end	Day	26% 12% 20% 20% 17% 5%	198
January	1st to 10th	Night	27% 7% 17% 26% 19% 4	760
	11th to 20th	Night	27% 5% 16% 28% 17% 7%	760
	21st to end	Night	26% 5% 13% 29% 22% 5%	836
February	1st to 10th	Night	23% 7% 15% 32% 20% 4	760
	11th to 20th	Night	23% 8% 17% 27% 19% 5%	744
	21st to end	Night	24% 7% 21% 31% 16% 2	628
March	1st to 10th	Night	31% 9% 15% 28% 14% 3	760
	11th to 20th	Night	28% 7% 12% 28% 22% 3	760
	21st to end	Night	27% 9% 17% 27% 17% 3	836
April	1st to 10th	Night	21% 8% 22% 26% 19% 4	760
	11th to 20th	Night	18% 11% 16% 29% 21% 5%	751
	21st to end	Night	11% 9% 18% 31% 25% 5%	698
May	1st to 10th	Night	10% 7% 22% 29% 25% 7%	570
	11th to 20th	Night	8% 4 16% 30% 36% 6%	542
	21st to end	Night	11% 7% 20% 26% 32% 5%	411
June	1st to 10th	Night	9% 7% 18% 32% 30% 4	380
	11th to 20th	Night	3 6% 19% 36% 32% 3	380
	21st to end	Night	4 1 8% 38% 43% 5%	380
July	1st to 10th	Night	3 1 9% 27% 50% 10%	375
	11th to 20th	Night	3 3 26% 51% 16%	552
	21st to end	Night	1 3 20% 55% 20%	624
August	1st to 10th	Night	2 2 4 24% 53% 14%	567
	11th to 20th	Night	2 1 4 29% 49% 16%	564
	21st to end	Night	4 2 5% 27% 48% 14%	835
September	1st to 10th	Night	3 2 7% 28% 46% 15%	760
	11th to 20th	Night	8% 3 10% 29% 39% 11%	760
	21st to end	Night	7% 3 10% 29% 36% 15%	760
October	1st to 10th	Night	7% 4 11% 31% 36% 11%	760
	11th to 20th	Night	13% 3 10% 26% 36% 12%	760
	21st to end	Night	15% 3 11% 28% 30% 12%	836
November	1st to 10th	Night	18% 4 16% 25% 29% 8%	780
	11th to 20th	Night	21% 5% 14% 32% 23% 6%	800
	21st to end	Night	19% 5% 14% 34% 22% 6%	800
December	1st to 10th	Night	26% 4 14% 29% 21% 7%	794
	11th to 20th	Night	31% 8% 13% 28% 17% 4	760
	21st to end	Night	31% 8% 17% 24% 16% 3	836

Page generated at 2024-12-06 00:54:47. Version ac07

Copyright © 2024 Attilla Danko.