White River Canyon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the White River Canyon clear sky chart from 2005-11-06 to 2024-11-10.

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	8% 13% 4 9% 6% 5% 5% 3 4 5% 39%	105448
	Night	8% 12% 4 10% 7% 6% 6% 4 5% 6% 33%	102386
Transparency	Day	39% 11% 11% 17% 14% 8%	105191
	Night	41% 14% 12% 15% 12% 6%	102232
Seeing	Day	18% 21% 29% 22% 9% 2	14603
	Night	16% 19% 23% 27% 14% 2	23581

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	9% 26% 9% 18% 10% 6% 4 4 3 3 9%	2539
	11th to 20th	Day	11% 23% 8% 13% 7% 5% 5% 3 3 5% 16%	2540
	21st to end	Day	15% 28% 6% 11% 6% 5% 4 3 4 5% 14%	2963
February	1st to 10th	Day	13% 19% 6% 13% 8% 5% 6% 5% 4 5% 17%	1710
	11th to 20th	Day	9% 17% 6% 14% 8% 8% 6% 4 5% 3 19%	1665
	21st to end	Day	8% 23% 7% 14% 7% 6% 5% 3 4 4 17%	1537
March	1st to 10th	Day	6% 19% 10% 14% 7% 6% 5% 4 5% 6% 18%	3192
	11th to 20th	Day	7% 18% 5% 10% 5% 4 3 3 3 4 38%	3490
	21st to end	Day	8% 27% 7% 15% 9% 6% 5% 3 3 3 14%	3974
April	1st to 10th	Day	12% 19% 6% 14% 8% 6% 6% 4 4 4 16%	2280
	11th to 20th	Day	11% 19% 6% 12% 8% 5% 5% 4 4 4 23%	2249
	21st to end	Day	8% 15% 4 11% 7% 6% 7% 5% 6% 7% 23%	2404
May	1st to 10th	Day	9% 15% 4 10% 7% 5% 4 4 4 4 33%	4420
	11th to 20th	Day	6% 7% 2 6% 5% 5% 5% 5% 5% 6% 48%	4377
	21st to end	Day	10% 13% 4 11% 7% 7% 7% 4 5% 6% 25%	4813
June	1st to 10th	Day	13% 13% 4 8% 6% 5% 5% 4 4 5% 33%	2660
	11th to 20th	Day	8% 11% 4 9% 7% 7% 7% 5% 6% 6% 32%	2660
	21st to end	Day	6% 5% 2 6% 4 4 4 3 5% 7% 54%	2660
July	1st to 10th	Day	1 2 1 3 1 2 3 2 3 5% 78%	4420
	11th to 20th	Day	2 2 1 2 2 2 2 2 3 4 78%	4420
	21st to end	Day	3 2 1 2 2 2 2 2 3 5% 76%	4790
August	1st to 10th	Day	2 3 1 4 2 3 3 3 4 5% 70%	4229
	11th to 20th	Day	2 3 1 5% 3 3 3 4 5% 7% 63%	4026
	21st to end	Day	5% 5% 2 6% 4 3 4 3 5% 6% 58%	4220
September	1st to 10th	Day	3 3 2 5% 4 4 4 3 4 7% 63%	2280
	11th to 20th	Day	6% 6% 3 6% 5% 4 6% 3 5% 8% 48%	2280
	21st to end	Day	9% 8% 3 7% 5% 4 3 3 5% 5% 48%	2023
October	1st to 10th	Day	7% 8% 3 7% 4 3 4 3 4 5% 53%	3180
	11th to 20th	Day	8% 10% 4 11% 7% 6% 5% 4 6% 6% 34%	3161
	21st to end	Day	10% 19% 5% 12% 7% 5% 6% 3 5% 5% 22%	3291
November	1st to 10th	Day	14% 19% 5% 13% 7% 6% 5% 4 4 5% 18%	1713
	11th to 20th	Day	11% 21% 6% 13% 8% 5% 7% 3 5% 5% 16%	1520
	21st to end	Day	11% 18% 5% 11% 9% 6% 6% 4 4 4 23%	1520
December	1st to 10th	Day	11% 17% 5% 12% 9% 7% 6% 4 4 3 23%	1520
	11th to 20th	Day	12% 20% 7% 12% 7% 7% 6% 4 6% 5% 14%	1928
	21st to end	Day	11% 22% 7% 14% 8% 6% 5% 4 3 4 15%	2794
January	1st to 10th	Night	11% 23% 6% 14% 12% 6% 6% 4 4 4 9%	4406
	11th to 20th	Night	14% 21% 8% 12% 8% 6% 5% 3 5% 5% 14%	4420
	21st to end	Night	16% 22% 7% 12% 6% 6% 5% 4 4 4 14%	4696
February	1st to 10th	Night	10% 17% 6% 13% 8% 6% 7% 5% 5% 6% 17%	2470
	11th to 20th	Night	10% 15% 5% 11% 10% 7% 6% 5% 5% 4 22%	2402
	21st to end	Night	9% 18% 6% 14% 9% 8% 6% 3 4 5% 17%	1915
March	1st to 10th	Night	7% 14% 6% 13% 8% 8% 7% 6% 7% 7% 18%	3679
	11th to 20th	Night	5% 14% 6% 10% 7% 5% 4 3 3 3 41%	3490
	21st to end	Night	9% 20% 6% 16% 10% 8% 6% 4 5% 4 11%	3679
April	1st to 10th	Night	11% 15% 6% 13% 9% 8% 7% 5% 4 4 19%	1900
	11th to 20th	Night	8% 12% 5% 11% 9% 8% 7% 5% 5% 6% 25%	1879
	21st to end	Night	8% 13% 4 9% 8% 7% 9% 5% 7% 7% 23%	1772
May	1st to 10th	Night	11% 14% 3 9% 6% 5% 5% 6% 6% 6% 29%	2540
	11th to 20th	Night	5% 6% 3 6% 7% 5% 7% 6% 6% 6% 44%	2516
	21st to end	Night	5% 12% 3 12% 7% 6% 7% 5% 8% 9% 27%	2762
June	1st to 10th	Night	13% 13% 4 8% 5% 5% 6% 4 6% 5% 32%	1520
	11th to 20th	Night	7% 8% 3 9% 7% 7% 7% 5% 7% 7% 33%	1520
	21st to end	Night	5% 6% 2 5% 3 4 4 3 5% 8% 54%	1520
July	1st to 10th	Night	2 1 1 2 2 2 2 2 3 6% 78%	2540
	11th to 20th	Night	2 2 1 3 2 2 3 2 3 5% 76%	2540
	21st to end	Night	2 2 1 3 1 2 2 2 3 7% 77%	2761
August	1st to 10th	Night	3 3 1 3 2 3 3 3 6% 6% 67%	2703
	11th to 20th	Night	3 2 1 3 3 4 5% 5% 7% 11% 57%	2812
	21st to end	Night	5% 4 2 4 2 3 3 4 5% 7% 61%	3456
September	1st to 10th	Night	3 3 1 3 3 4 4 4 6% 7% 63%	1900
	11th to 20th	Night	6% 6% 2 6% 6% 5% 5% 4 6% 7% 47%	1900
	21st to end	Night	8% 7% 3 7% 4 4 5% 4 6% 8% 47%	2154
October	1st to 10th	Night	6% 6% 3 6% 4 3 4 3 5% 6% 53%	3800
	11th to 20th	Night	8% 10% 4 9% 6% 5% 6% 4 5% 7% 35%	3777
	21st to end	Night	12% 14% 6% 12% 7% 6% 7% 4 4 4 24%	4272
November	1st to 10th	Night	14% 15% 4 13% 8% 7% 7% 4 4 4 20%	2567
	11th to 20th	Night	12% 16% 5% 13% 9% 7% 7% 5% 5% 5% 17%	2660
	21st to end	Night	8% 15% 4 13% 8% 7% 7% 5% 6% 5% 23%	2660
December	1st to 10th	Night	11% 15% 5% 11% 8% 7% 5% 4 5% 4 23%	2660
	11th to 20th	Night	12% 17% 6% 14% 9% 8% 7% 4 6% 5% 13%	3276
	21st to end	Night	11% 16% 6% 14% 8% 7% 7% 5% 4 5% 17%	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	61% 20% 10% 6% 2	2539
	11th to 20th	Day	62% 15% 9% 9% 3 2	2540
	21st to end	Day	65% 15% 7% 7% 4 1	2963
February	1st to 10th	Day	60% 14% 13% 10% 3	1710
	11th to 20th	Day	57% 14% 11% 12% 5% 1	1674
	21st to end	Day	59% 13% 12% 9% 6% 1	1537
March	1st to 10th	Day	50% 15% 16% 13% 6% 1	3192
	11th to 20th	Day	42% 13% 7% 28% 10%	3490
	21st to end	Day	60% 18% 9% 9% 4	3974
April	1st to 10th	Day	58% 16% 12% 10% 4	2280
	11th to 20th	Day	56% 11% 13% 9% 9% 2	2252
	21st to end	Day	48% 16% 13% 14% 7% 2	2404
May	1st to 10th	Day	41% 12% 16% 21% 9%	4420
	11th to 20th	Day	26% 8% 19% 30% 16%	4380
	21st to end	Day	42% 21% 18% 15% 3	4814
June	1st to 10th	Day	46% 10% 14% 19% 9% 1	2660
	11th to 20th	Day	39% 15% 16% 19% 8% 3	2660
	21st to end	Day	25% 9% 12% 29% 20% 5%	2660
July	1st to 10th	Day	9% 5% 8% 14% 22% 43%	4351
	11th to 20th	Day	10% 4 4 10% 25% 47%	4345
	21st to end	Day	11% 4 8% 18% 37% 23%	4639
August	1st to 10th	Day	14% 5% 8% 17% 35% 21%	4213
	11th to 20th	Day	17% 6% 9% 38% 25% 6%	4065
	21st to end	Day	22% 7% 11% 24% 28% 8%	4219
September	1st to 10th	Day	16% 8% 10% 25% 28% 14%	2280
	11th to 20th	Day	29% 9% 13% 22% 20% 7%	2280
	21st to end	Day	33% 8% 12% 20% 19% 7%	2023
October	1st to 10th	Day	30% 7% 7% 20% 30% 7%	3180
	11th to 20th	Day	42% 9% 13% 20% 14% 1	3161
	21st to end	Day	51% 14% 9% 16% 10% 1	3291
November	1st to 10th	Day	58% 12% 11% 12% 6% 1	1713
	11th to 20th	Day	61% 15% 10% 8% 5% 1	1520
	21st to end	Day	56% 13% 9% 8% 13% 1	1520
December	1st to 10th	Day	57% 14% 8% 13% 7% 1	1520
	11th to 20th	Day	61% 15% 11% 9% 4	1928
	21st to end	Day	65% 12% 9% 11% 2 1	2794
January	1st to 10th	Night	62% 20% 11% 5% 2	4406
	11th to 20th	Night	61% 15% 12% 8% 3 2	4420
	21st to end	Night	63% 15% 10% 6% 5% 1	4696
February	1st to 10th	Night	57% 18% 10% 11% 4	2470
	11th to 20th	Night	53% 16% 12% 10% 8% 1	2404
	21st to end	Night	56% 16% 11% 10% 7% 1	1915
March	1st to 10th	Night	43% 19% 17% 15% 5% 1	3679
	11th to 20th	Night	36% 15% 10% 30% 8% 1	3490
	21st to end	Night	53% 26% 12% 8% 2	3679
April	1st to 10th	Night	51% 20% 13% 11% 4	1900
	11th to 20th	Night	46% 17% 14% 11% 8% 3	1879
	21st to end	Night	43% 20% 14% 14% 7% 2	1772
May	1st to 10th	Night	39% 14% 18% 18% 10% 1	2540
	11th to 20th	Night	24% 14% 20% 28% 14% 1	2516
	21st to end	Night	31% 29% 23% 12% 4	2762
June	1st to 10th	Night	44% 13% 13% 19% 9% 2	1520
	11th to 20th	Night	34% 19% 18% 20% 7% 3	1520
	21st to end	Night	24% 10% 14% 26% 21% 6%	1520
July	1st to 10th	Night	9% 5% 8% 12% 22% 44%	2500
	11th to 20th	Night	11% 4 7% 10% 19% 49%	2492
	21st to end	Night	9% 4 9% 16% 34% 29%	2674
August	1st to 10th	Night	13% 6% 8% 15% 36% 22%	2695
	11th to 20th	Night	14% 7% 15% 33% 24% 8%	2839
	21st to end	Night	18% 7% 13% 24% 28% 10%	3456
September	1st to 10th	Night	13% 7% 15% 24% 27% 14%	1900
	11th to 20th	Night	27% 11% 13% 19% 19% 11%	1900
	21st to end	Night	28% 11% 13% 21% 18% 9%	2154
October	1st to 10th	Night	27% 7% 9% 21% 31% 4	3800
	11th to 20th	Night	38% 11% 13% 22% 13% 3	3777
	21st to end	Night	49% 14% 10% 13% 12% 1	4272
November	1st to 10th	Night	55% 15% 10% 12% 7% 1	2567
	11th to 20th	Night	57% 17% 9% 10% 7%	2660
	21st to end	Night	49% 15% 11% 11% 12% 2	2660
December	1st to 10th	Night	53% 15% 12% 13% 7%	2660
	11th to 20th	Night	61% 17% 10% 7% 5%	3276
	21st to end	Night	56% 17% 16% 8% 2 1	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	34% 27% 21% 13% 5% 1	180
	11th to 20th	Day	28% 26% 26% 13% 7% 1	180
	21st to end	Day	23% 28% 24% 18% 7%	302
February	1st to 10th	Day	26% 31% 23% 14% 6%	370
	11th to 20th	Day	27% 30% 28% 13% 2	365
	21st to end	Day	29% 25% 25% 16% 4	367
March	1st to 10th	Day	24% 27% 32% 13% 4 1	460
	11th to 20th	Day	22% 27% 28% 16% 6% 2	460
	21st to end	Day	30% 30% 24% 13% 4	506
April	1st to 10th	Day	27% 27% 23% 15% 6% 1	460
	11th to 20th	Day	28% 29% 24% 13% 4 2	452
	21st to end	Day	23% 28% 26% 18% 5% 1	460
May	1st to 10th	Day	20% 23% 29% 18% 8% 2	463
	11th to 20th	Day	23% 20% 27% 18% 9% 3	488
	21st to end	Day	18% 20% 25% 27% 8% 3	529
June	1st to 10th	Day	18% 20% 27% 23% 10% 3	490
	11th to 20th	Day	20% 26% 30% 18% 6% 1	490
	21st to end	Day	8% 15% 36% 27% 12% 2	490
July	1st to 10th	Day	4 14% 37% 33% 10% 2	486
	11th to 20th	Day	4 14% 38% 28% 13% 3	484
	21st to end	Day	3 9% 35% 33% 16% 4	531
August	1st to 10th	Day	3 9% 37% 30% 15% 6%	487
	11th to 20th	Day	5% 8% 32% 35% 15% 6%	477
	21st to end	Day	8% 15% 32% 30% 11% 5%	539
September	1st to 10th	Day	4 14% 35% 31% 13% 3	490
	11th to 20th	Day	14% 12% 31% 29% 13% 1	490
	21st to end	Day	14% 19% 31% 25% 11% 1	490
October	1st to 10th	Day	20% 16% 29% 25% 9% 1	490
	11th to 20th	Day	21% 22% 22% 22% 12% 1	490
	21st to end	Day	27% 28% 21% 14% 9% 2	444
November	1st to 10th	Day	27% 24% 24% 18% 6% 1	275
	11th to 20th	Day	29% 23% 19% 20% 7% 2	180
	21st to end	Day	23% 21% 27% 23% 6% 1	180
December	1st to 10th	Day	24% 20% 25% 18% 8% 4	180
	11th to 20th	Day	25% 29% 28% 12% 5%	180
	21st to end	Day	25% 28% 21% 17% 7% 2	198
January	1st to 10th	Night	27% 24% 21% 18% 10% 1	760
	11th to 20th	Night	22% 21% 23% 21% 10% 2	760
	21st to end	Night	19% 19% 24% 27% 9% 1	836
February	1st to 10th	Night	21% 22% 23% 24% 9% 1	760
	11th to 20th	Night	22% 23% 21% 24% 10% 1	744
	21st to end	Night	22% 24% 25% 22% 6% 1	628
March	1st to 10th	Night	17% 24% 23% 24% 10% 1	760
	11th to 20th	Night	14% 24% 24% 26% 10% 1	760
	21st to end	Night	20% 28% 25% 18% 8% 2	836
April	1st to 10th	Night	21% 21% 26% 20% 10% 1	760
	11th to 20th	Night	14% 27% 27% 17% 12% 3	751
	21st to end	Night	14% 26% 25% 22% 12% 1	632
May	1st to 10th	Night	13% 23% 23% 24% 15% 2	380
	11th to 20th	Night	14% 14% 20% 30% 19% 3	374
	21st to end	Night	10% 16% 25% 33% 14% 2	411
June	1st to 10th	Night	18% 16% 21% 29% 14% 1	380
	11th to 20th	Night	9% 23% 28% 27% 13% 1	380
	21st to end	Night	9% 10% 24% 39% 17% 1	380
July	1st to 10th	Night	5% 5% 28% 41% 21% 1	370
	11th to 20th	Night	2 5% 33% 42% 16% 2	368
	21st to end	Night	3 5% 22% 47% 21% 2	416
August	1st to 10th	Night	3 4 21% 42% 25% 5%	474
	11th to 20th	Night	4 3 17% 35% 31% 10%	564
	21st to end	Night	5% 8% 26% 35% 23% 4	807
September	1st to 10th	Night	5% 7% 22% 39% 23% 4	760
	11th to 20th	Night	9% 9% 21% 29% 27% 4	760
	21st to end	Night	13% 10% 20% 33% 22% 2	760
October	1st to 10th	Night	13% 13% 26% 29% 16% 4	760
	11th to 20th	Night	15% 16% 20% 27% 18% 4	760
	21st to end	Night	20% 23% 19% 24% 12% 3	836
November	1st to 10th	Night	22% 20% 24% 24% 9% 1	778
	11th to 20th	Night	21% 27% 22% 21% 8% 1	760
	21st to end	Night	16% 23% 23% 26% 11% 1	760
December	1st to 10th	Night	18% 21% 23% 25% 12% 1	760
	11th to 20th	Night	22% 23% 28% 19% 8% 1	760
	21st to end	Night	23% 28% 23% 19% 6% 1	836

Page generated at 2024-11-07 03:55:49. Version ac07

Copyright © 2024 Attilla Danko.