Peyton
Clear Sky Chart
History

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

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 5% 2 5% 4 4 4 4 6% 8% 54%	105167
	Night	4 5% 2 5% 4 4 4 4 6% 8% 55%	102694
Transparency	Day	25% 7% 11% 23% 24% 11%	104910
	Night	25% 6% 12% 24% 23% 9%	102541
Seeing	Day	7% 9% 29% 30% 19% 6%	15571
	Night	6% 6% 31% 40% 15% 2	25568

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	1 4 1 4 3 4 5% 4 6% 8% 60%	2538
	11th to 20th	Day	1 3 2 5% 4 4 4 4 7% 9% 56%	2604
	21st to end	Day	2 5% 2 6% 4 3 4 3 5% 7% 60%	3146
February	1st to 10th	Day	2 9% 3 5% 4 3 4 3 5% 7% 57%	1746
	11th to 20th	Day	1 4 2 6% 5% 4 4 4 5% 8% 56%	1849
	21st to end	Day	1 5% 3 7% 4 4 3 3 5% 6% 58%	1570
March	1st to 10th	Day	2 6% 3 6% 4 4 3 4 5% 6% 58%	3130
	11th to 20th	Day	4 11% 3 6% 4 4 3 3 6% 6% 51%	3384
	21st to end	Day	3 7% 2 6% 4 4 5% 4 7% 8% 52%	4100
April	1st to 10th	Day	5% 7% 1 4 3 3 5% 3 5% 8% 55%	2280
	11th to 20th	Day	6% 9% 3 6% 3 4 5% 4 6% 8% 47%	2251
	21st to end	Day	8% 7% 2 6% 4 4 4 4 6% 8% 47%	2280
May	1st to 10th	Day	9% 7% 2 6% 4 4 4 4 6% 7% 47%	4024
	11th to 20th	Day	8% 7% 2 7% 4 4 5% 5% 7% 9% 43%	4250
	21st to end	Day	5% 4 1 5% 4 4 6% 5% 8% 10% 48%	4825
June	1st to 10th	Day	6% 5% 1 4 4 5% 5% 5% 7% 10% 49%	2660
	11th to 20th	Day	4 4 2 4 3 4 5% 4 8% 9% 53%	2660
	21st to end	Day	4 3 1 5% 5% 5% 5% 5% 9% 9% 48%	2660
July	1st to 10th	Day	4 3 1 5% 4 5% 5% 5% 8% 10% 49%	4430
	11th to 20th	Day	4 3 1 5% 5% 6% 6% 5% 8% 10% 46%	4430
	21st to end	Day	4 4 2 5% 5% 5% 6% 4 7% 8% 51%	4744
August	1st to 10th	Day	8% 5% 2 6% 5% 5% 6% 5% 9% 10% 39%	3985
	11th to 20th	Day	4 4 1 5% 4 5% 5% 6% 9% 10% 48%	3726
	21st to end	Day	4 4 2 5% 4 5% 5% 5% 8% 9% 49%	4180
September	1st to 10th	Day	4 4 1 4 4 4 4 4 6% 9% 56%	2280
	11th to 20th	Day	6% 3 1 4 3 3 4 3 5% 8% 60%	2229
	21st to end	Day	5% 3 1 4 3 3 3 3 4 6% 65%	2090
October	1st to 10th	Day	4 4 1 2 1 2 2 2 3 5% 74%	3275
	11th to 20th	Day	5% 5% 2 4 3 3 3 3 4 7% 61%	3150
	21st to end	Day	3 3 1 3 3 2 2 2 4 5% 71%	3287
November	1st to 10th	Day	2 4 1 4 2 2 3 4 5% 7% 65%	1763
	11th to 20th	Day	2 6% 2 4 3 3 4 2 3 7% 65%	1710
	21st to end	Day	2 6% 2 4 3 2 3 3 5% 7% 64%	1691
December	1st to 10th	Day	1 5% 2 4 4 4 4 4 5% 8% 59%	1520
	11th to 20th	Day	2 5% 2 6% 4 3 4 3 5% 7% 57%	1926
	21st to end	Day	2 6% 2 6% 3 4 4 3 5% 6% 59%	2794
January	1st to 10th	Night	1 6% 3 6% 4 3 4 4 6% 7% 56%	4417
	11th to 20th	Night	1 3 1 4 4 4 4 3 6% 7% 62%	4394
	21st to end	Night	2 5% 2 6% 4 4 4 3 4 7% 60%	4521
February	1st to 10th	Night	2 7% 2 6% 4 4 4 3 5% 7% 57%	2432
	11th to 20th	Night	2 6% 3 7% 5% 4 4 4 6% 7% 52%	2218
	21st to end	Night	2 6% 2 5% 4 4 3 3 4 6% 62%	1884
March	1st to 10th	Night	1 6% 3 7% 3 3 4 3 5% 6% 59%	3734
	11th to 20th	Night	6% 10% 3 6% 4 3 4 3 5% 6% 51%	3591
	21st to end	Night	3 6% 2 6% 4 4 4 4 6% 8% 53%	3543
April	1st to 10th	Night	5% 6% 2 5% 3 4 3 3 6% 6% 56%	1900
	11th to 20th	Night	7% 10% 2 5% 4 4 3 3 5% 7% 49%	1877
	21st to end	Night	9% 8% 2 4 4 4 4 4 5% 8% 47%	1900
May	1st to 10th	Night	9% 6% 2 6% 5% 4 4 3 6% 7% 49%	2930
	11th to 20th	Night	8% 7% 3 5% 4 4 4 4 6% 9% 45%	2652
	21st to end	Night	7% 6% 2 6% 4 4 5% 4 5% 8% 50%	2762
June	1st to 10th	Night	4 4 2 5% 3 4 4 5% 7% 10% 52%	1520
	11th to 20th	Night	3 3 1 3 3 4 4 5% 7% 8% 58%	1520
	21st to end	Night	5% 4 2 6% 4 4 6% 5% 7% 9% 49%	1520
July	1st to 10th	Night	6% 4 2 5% 5% 5% 5% 4 6% 8% 50%	2540
	11th to 20th	Night	3 3 1 6% 5% 4 6% 5% 8% 11% 48%	2540
	21st to end	Night	4 4 1 5% 4 4 4 4 7% 9% 54%	2815
August	1st to 10th	Night	7% 7% 3 8% 6% 6% 6% 6% 8% 10% 34%	2939
	11th to 20th	Night	4 4 3 7% 5% 5% 6% 5% 7% 10% 44%	3113
	21st to end	Night	3 3 1 5% 4 5% 6% 6% 9% 11% 46%	3487
September	1st to 10th	Night	5% 5% 1 6% 4 4 4 5% 6% 9% 51%	1900
	11th to 20th	Night	5% 3 2 3 4 3 3 3 5% 8% 60%	1950
	21st to end	Night	5% 4 1 5% 3 4 4 3 4 5% 63%	2090
October	1st to 10th	Night	4 3 1 4 2 3 3 2 3 5% 70%	3689
	11th to 20th	Night	6% 4 2 5% 3 3 4 4 5% 7% 57%	3778
	21st to end	Night	3 4 1 3 2 3 3 3 4 5% 68%	4238
November	1st to 10th	Night	2 5% 2 3 3 2 3 2 6% 7% 65%	2535
	11th to 20th	Night	1 4 1 4 3 3 3 3 4 6% 68%	2477
	21st to end	Night	3 5% 2 5% 3 3 3 3 5% 7% 61%	2484
December	1st to 10th	Night	1 5% 2 5% 4 3 4 3 5% 7% 61%	2660
	11th to 20th	Night	2 4 2 5% 4 4 4 4 5% 8% 58%	3271
	21st to end	Night	3 5% 2 5% 4 4 5% 4 6% 7% 55%	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% 6% 11% 30% 26% 8%	2539
	11th to 20th	Day	21% 5% 15% 29% 22% 9%	2604
	21st to end	Day	24% 5% 10% 29% 25% 6%	3146
February	1st to 10th	Day	26% 4 12% 26% 21% 10%	1746
	11th to 20th	Day	24% 6% 8% 27% 27% 8%	1859
	21st to end	Day	26% 4 8% 22% 24% 16%	1570
March	1st to 10th	Day	21% 7% 10% 18% 30% 14%	3130
	11th to 20th	Day	29% 7% 12% 30% 17% 5%	3384
	21st to end	Day	24% 9% 11% 30% 22% 4	4100
April	1st to 10th	Day	26% 6% 12% 24% 22% 10%	2280
	11th to 20th	Day	32% 7% 11% 22% 18% 10%	2254
	21st to end	Day	32% 7% 12% 26% 20% 4	2280
May	1st to 10th	Day	31% 7% 11% 24% 15% 11%	4024
	11th to 20th	Day	32% 9% 16% 22% 20% 3	4254
	21st to end	Day	23% 10% 16% 22% 19% 9%	4825
June	1st to 10th	Day	26% 7% 16% 23% 17% 9%	2660
	11th to 20th	Day	23% 7% 12% 18% 23% 16%	2660
	21st to end	Day	25% 8% 13% 21% 21% 12%	2660
July	1st to 10th	Day	25% 9% 10% 16% 26% 13%	4361
	11th to 20th	Day	26% 9% 11% 22% 22% 10%	4355
	21st to end	Day	27% 7% 11% 18% 19% 18%	4594
August	1st to 10th	Day	35% 9% 17% 24% 11% 5%	3971
	11th to 20th	Day	27% 8% 13% 18% 21% 13%	3762
	21st to end	Day	27% 6% 13% 21% 25% 7%	4179
September	1st to 10th	Day	23% 5% 10% 21% 25% 16%	2280
	11th to 20th	Day	21% 6% 9% 17% 29% 18%	2229
	21st to end	Day	20% 4 7% 20% 35% 14%	2090
October	1st to 10th	Day	14% 4 6% 15% 39% 21%	3275
	11th to 20th	Day	23% 4 7% 24% 32% 10%	3150
	21st to end	Day	16% 3 4 23% 38% 16%	3287
November	1st to 10th	Day	17% 4 10% 23% 28% 18%	1763
	11th to 20th	Day	20% 4 6% 26% 34% 10%	1710
	21st to end	Day	21% 3 9% 22% 28% 18%	1691
December	1st to 10th	Day	23% 5% 13% 26% 24% 8%	1520
	11th to 20th	Day	25% 5% 10% 23% 29% 9%	1924
	21st to end	Day	23% 6% 11% 26% 23% 11%	2794
January	1st to 10th	Night	24% 6% 10% 27% 28% 5%	4417
	11th to 20th	Night	18% 7% 13% 29% 24% 10%	4394
	21st to end	Night	24% 6% 11% 33% 22% 5%	4521
February	1st to 10th	Night	26% 5% 10% 27% 23% 9%	2432
	11th to 20th	Night	28% 5% 11% 27% 21% 8%	2218
	21st to end	Night	22% 4 8% 26% 26% 14%	1884
March	1st to 10th	Night	22% 6% 10% 18% 32% 13%	3734
	11th to 20th	Night	31% 5% 15% 21% 23% 4	3591
	21st to end	Night	24% 8% 15% 28% 22% 3	3543
April	1st to 10th	Night	26% 6% 13% 23% 22% 10%	1900
	11th to 20th	Night	33% 5% 14% 23% 18% 7%	1877
	21st to end	Night	33% 8% 13% 25% 16% 5%	1900
May	1st to 10th	Night	30% 8% 14% 24% 15% 9%	2930
	11th to 20th	Night	32% 10% 17% 25% 10% 7%	2653
	21st to end	Night	28% 10% 16% 23% 17% 6%	2762
June	1st to 10th	Night	25% 8% 22% 23% 15% 8%	1520
	11th to 20th	Night	20% 7% 16% 23% 18% 16%	1520
	21st to end	Night	27% 9% 10% 23% 21% 10%	1520
July	1st to 10th	Night	29% 7% 11% 21% 26% 6%	2500
	11th to 20th	Night	24% 8% 16% 29% 18% 4	2492
	21st to end	Night	23% 9% 14% 22% 17% 14%	2727
August	1st to 10th	Night	41% 9% 18% 19% 9% 4	2930
	11th to 20th	Night	32% 9% 16% 20% 18% 5%	3143
	21st to end	Night	26% 8% 18% 27% 17% 4	3487
September	1st to 10th	Night	27% 7% 11% 22% 23% 10%	1900
	11th to 20th	Night	22% 5% 10% 22% 26% 15%	1950
	21st to end	Night	22% 5% 8% 23% 31% 10%	2090
October	1st to 10th	Night	17% 4 8% 19% 35% 17%	3689
	11th to 20th	Night	25% 4 8% 28% 26% 9%	3778
	21st to end	Night	18% 4 7% 27% 29% 15%	4238
November	1st to 10th	Night	18% 3 11% 24% 27% 16%	2535
	11th to 20th	Night	18% 4 8% 28% 31% 11%	2477
	21st to end	Night	23% 4 10% 22% 29% 13%	2484
December	1st to 10th	Night	22% 5% 12% 26% 25% 9%	2660
	11th to 20th	Night	23% 6% 9% 22% 33% 6%	3272
	21st to end	Night	25% 6% 13% 23% 24% 10%	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	5% 7% 31% 36% 17% 4	270
	11th to 20th	Day	7% 12% 31% 35% 13% 1	270
	21st to end	Day	3 12% 34% 31% 16% 3	297
February	1st to 10th	Day	4 12% 45% 29% 9% 2	270
	11th to 20th	Day	4 11% 44% 30% 10% 1	270
	21st to end	Day	15% 48% 28% 7% 1	225
March	1st to 10th	Day	4 11% 38% 30% 14% 4	270
	11th to 20th	Day	9% 15% 38% 25% 10% 4	393
	21st to end	Day	10% 22% 42% 17% 7% 2	506
April	1st to 10th	Day	10% 17% 40% 21% 9% 2	460
	11th to 20th	Day	13% 21% 38% 18% 6% 3	452
	21st to end	Day	13% 18% 34% 24% 10% 1	460
May	1st to 10th	Day	12% 17% 32% 26% 10% 2	596
	11th to 20th	Day	13% 10% 29% 27% 17% 4	675
	21st to end	Day	8% 11% 32% 26% 18% 5%	734
June	1st to 10th	Day	6% 8% 23% 32% 22% 8%	680
	11th to 20th	Day	6% 9% 30% 32% 19% 5%	680
	21st to end	Day	5% 6% 25% 34% 23% 7%	680
July	1st to 10th	Day	6% 3 18% 32% 31% 10%	671
	11th to 20th	Day	5% 1 14% 33% 33% 13%	668
	21st to end	Day	7% 2 14% 29% 34% 14%	705
August	1st to 10th	Day	8% 1 18% 34% 28% 9%	487
	11th to 20th	Day	5% 3 23% 33% 25% 12%	477
	21st to end	Day	4 3 24% 36% 23% 9%	539
September	1st to 10th	Day	6% 3 24% 33% 24% 10%	490
	11th to 20th	Day	5% 5% 27% 29% 23% 11%	439
	21st to end	Day	8% 7% 18% 31% 23% 14%	300
October	1st to 10th	Day	8% 9% 19% 27% 20% 16%	300
	11th to 20th	Day	3 10% 29% 32% 17% 9%	300
	21st to end	Day	8% 11% 29% 30% 16% 6%	330
November	1st to 10th	Day	5% 11% 34% 26% 18% 6%	300
	11th to 20th	Day	5% 7% 31% 35% 19% 3	270
	21st to end	Day	4 12% 33% 31% 14% 5%	270
December	1st to 10th	Day	2 13% 38% 31% 14% 3	270
	11th to 20th	Day	3 10% 36% 34% 16% 1	270
	21st to end	Day	5% 12% 39% 32% 11% 1	297
January	1st to 10th	Night	4 6% 35% 41% 11% 3	950
	11th to 20th	Night	3 7% 38% 39% 10% 3	927
	21st to end	Night	3 4 38% 43% 11% 1	836
February	1st to 10th	Night	4 6% 46% 38% 6% 1	760
	11th to 20th	Night	4 6% 46% 35% 8% 1	744
	21st to end	Night	5% 8% 46% 35% 5%	628
March	1st to 10th	Night	4 6% 41% 39% 8% 1	760
	11th to 20th	Night	7% 7% 35% 39% 11% 1	760
	21st to end	Night	6% 8% 44% 34% 8%	667
April	1st to 10th	Night	8% 9% 45% 30% 7%	570
	11th to 20th	Night	14% 12% 33% 33% 7% 1	563
	21st to end	Night	13% 12% 30% 36% 8% 1	570
May	1st to 10th	Night	9% 11% 34% 35% 11% 1	570
	11th to 20th	Night	12% 7% 28% 39% 13% 1	561
	21st to end	Night	10% 7% 35% 33% 14% 1	617
June	1st to 10th	Night	5% 4 27% 42% 19% 2	570
	11th to 20th	Night	4 5% 29% 47% 14% 1	570
	21st to end	Night	4 4 22% 46% 21% 2	570
July	1st to 10th	Night	7% 3 17% 44% 28% 2	555
	11th to 20th	Night	5% 1 11% 45% 36% 3	552
	21st to end	Night	7% 2 12% 38% 38% 2	624
August	1st to 10th	Night	7% 3 12% 42% 32% 3	567
	11th to 20th	Night	6% 2 13% 52% 24% 2	564
	21st to end	Night	6% 2 13% 46% 30% 3	627
September	1st to 10th	Night	6% 3 14% 48% 25% 3	570
	11th to 20th	Night	7% 2 19% 45% 23% 3	570
	21st to end	Night	7% 4 23% 42% 21% 3	570
October	1st to 10th	Night	9% 6% 29% 34% 19% 3	688
	11th to 20th	Night	4 5% 31% 39% 17% 4	760
	21st to end	Night	6% 7% 29% 38% 17% 3	905
November	1st to 10th	Night	3 6% 29% 43% 16% 2	975
	11th to 20th	Night	3 6% 35% 43% 11% 2	953
	21st to end	Night	5% 7% 33% 37% 15% 2	950
December	1st to 10th	Night	3 6% 39% 41% 10% 2	950
	11th to 20th	Night	4 6% 39% 38% 11% 1	950
	21st to end	Night	6% 9% 40% 37% 8% 1	1045

Page generated at 2024-11-08 04:44:51. Version ac07

Copyright © 2024 Attilla Danko.