Antelope
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Antelope clear sky chart from 2005-11-06 to 2024-11-01.

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	6% 7% 3 7% 5% 4 4 4 5% 6% 49%	101509
	Night	7% 8% 3 8% 5% 5% 5% 4 6% 7% 44%	97604
Transparency	Day	34% 6% 11% 21% 17% 10%	101252
	Night	38% 8% 13% 21% 14% 6%	97450
Seeing	Day	10% 13% 24% 28% 19% 6%	14560
	Night	10% 8% 19% 38% 22% 3	23585

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	10% 12% 5% 14% 9% 8% 7% 6% 7% 7% 14%	2539
	11th to 20th	Day	13% 16% 6% 14% 7% 5% 7% 4 4 4 19%	2540
	21st to end	Day	10% 14% 5% 11% 6% 5% 7% 6% 7% 9% 20%	2900
February	1st to 10th	Day	9% 13% 3 10% 6% 6% 5% 5% 6% 8% 28%	1710
	11th to 20th	Day	10% 11% 4 10% 6% 5% 5% 4 7% 8% 30%	1684
	21st to end	Day	8% 13% 4 9% 8% 6% 6% 5% 7% 7% 27%	1570
March	1st to 10th	Day	6% 11% 3 10% 6% 6% 5% 6% 7% 9% 31%	3138
	11th to 20th	Day	5% 9% 3 7% 5% 4 5% 2 5% 7% 47%	3458
	21st to end	Day	7% 10% 4 10% 7% 7% 7% 6% 8% 9% 26%	4036
April	1st to 10th	Day	10% 12% 3 9% 6% 6% 6% 5% 6% 7% 29%	2280
	11th to 20th	Day	8% 11% 4 8% 7% 5% 5% 4 5% 6% 38%	2249
	21st to end	Day	7% 8% 3 7% 5% 6% 5% 4 8% 7% 41%	2370
May	1st to 10th	Day	9% 7% 2 6% 4 4 4 4 6% 7% 45%	4420
	11th to 20th	Day	5% 4 1 4 3 3 4 3 5% 6% 62%	4377
	21st to end	Day	8% 7% 2 7% 5% 4 4 5% 7% 8% 44%	4813
June	1st to 10th	Day	9% 8% 2 7% 5% 4 5% 4 6% 7% 43%	2660
	11th to 20th	Day	7% 6% 2 5% 4 4 4 4 5% 7% 51%	2660
	21st to end	Day	4 3 2 3 3 3 3 3 4 5% 67%	2660
July	1st to 10th	Day	1 1 1 2 1 1 1 2 2 3 84%	4420
	11th to 20th	Day	2 1 1 2 1 2 2 2 2 4 82%	4420
	21st to end	Day	2 2 1 2 1 2 2 2 3 5% 80%	4790
August	1st to 10th	Day	3 3 1 3 2 2 2 2 3 5% 73%	4312
	11th to 20th	Day	2 2 1 3 3 2 3 2 3 6% 73%	3978
	21st to end	Day	3 3 1 3 2 2 3 2 3 5% 72%	4180
September	1st to 10th	Day	2 2 1 2 2 2 2 2 4 5% 75%	2280
	11th to 20th	Day	4 4 2 4 4 3 4 4 5% 7% 58%	2280
	21st to end	Day	8% 4 1 5% 3 4 3 3 4 6% 57%	2045
October	1st to 10th	Day	9% 8% 2 6% 4 4 4 3 5% 5% 50%	1900
	11th to 20th	Day	7% 6% 2 6% 5% 5% 5% 4 6% 9% 45%	1900
	21st to end	Day	9% 9% 3 8% 5% 5% 6% 3 5% 6% 40%	1958
November	1st to 10th	Day	10% 9% 4 9% 6% 6% 5% 5% 8% 8% 30%	1674
	11th to 20th	Day	9% 11% 5% 10% 8% 7% 6% 5% 7% 8% 24%	1546
	21st to end	Day	8% 12% 4 8% 6% 6% 6% 5% 6% 9% 30%	1520
December	1st to 10th	Day	7% 10% 5% 10% 8% 7% 6% 5% 5% 6% 31%	1520
	11th to 20th	Day	9% 12% 6% 15% 9% 7% 6% 5% 8% 7% 16%	1928
	21st to end	Day	10% 15% 5% 13% 8% 7% 8% 6% 7% 6% 15%	2794
January	1st to 10th	Night	8% 12% 6% 15% 11% 8% 7% 5% 7% 6% 14%	4406
	11th to 20th	Night	15% 16% 5% 12% 7% 5% 5% 5% 5% 7% 19%	4420
	21st to end	Night	10% 13% 5% 12% 8% 6% 6% 5% 7% 8% 20%	4755
February	1st to 10th	Night	9% 12% 4 10% 7% 6% 5% 4 6% 7% 29%	2470
	11th to 20th	Night	9% 11% 4 10% 6% 5% 5% 4 6% 6% 35%	2383
	21st to end	Night	9% 13% 5% 9% 7% 6% 6% 5% 6% 8% 28%	1884
March	1st to 10th	Night	5% 8% 4 8% 6% 7% 6% 5% 8% 10% 33%	3736
	11th to 20th	Night	4 7% 2 7% 4 4 4 4 5% 8% 51%	3521
	21st to end	Night	6% 10% 3 10% 7% 7% 9% 6% 7% 9% 26%	3617
April	1st to 10th	Night	9% 10% 3 9% 6% 5% 5% 4 6% 9% 34%	1900
	11th to 20th	Night	6% 10% 4 7% 6% 4 5% 4 6% 7% 41%	1879
	21st to end	Night	6% 8% 3 7% 6% 5% 6% 6% 6% 7% 41%	1806
May	1st to 10th	Night	9% 8% 3 6% 4 3 3 3 5% 5% 50%	2540
	11th to 20th	Night	5% 3 1 3 2 2 3 3 4 6% 67%	2516
	21st to end	Night	5% 6% 2 6% 4 3 5% 3 6% 8% 52%	2762
June	1st to 10th	Night	9% 7% 3 6% 4 4 3 4 6% 7% 47%	1520
	11th to 20th	Night	6% 5% 2 5% 3 4 4 4 6% 7% 55%	1520
	21st to end	Night	5% 4 1 3 2 2 3 2 4 5% 68%	1520
July	1st to 10th	Night	1 1 1 1 1 2 1 2 3 86%	2540
	11th to 20th	Night	1 1 2 2 2 2 2 2 4 81%	2540
	21st to end	Night	1 1 2 2 1 1 2 3 4 82%	2761
August	1st to 10th	Night	2 2 1 3 2 3 3 2 5% 5% 71%	2617
	11th to 20th	Night	2 1 1 2 2 3 3 3 4 6% 74%	2862
	21st to end	Night	2 2 1 3 2 2 3 2 4 5% 75%	3498
September	1st to 10th	Night	2 2 1 2 1 1 2 2 3 5% 77%	1900
	11th to 20th	Night	4 3 1 4 3 4 5% 3 5% 7% 62%	1900
	21st to end	Night	6% 4 2 4 3 3 3 3 5% 7% 60%	2132
October	1st to 10th	Night	7% 6% 2 6% 3 3 3 3 4 5% 57%	2280
	11th to 20th	Night	7% 6% 2 6% 5% 4 4 4 6% 8% 48%	2280
	21st to end	Night	8% 7% 3 8% 5% 5% 5% 3 6% 6% 44%	2639
November	1st to 10th	Night	10% 10% 4 9% 6% 6% 5% 5% 6% 8% 32%	2411
	11th to 20th	Night	10% 9% 4 11% 6% 6% 6% 6% 7% 8% 27%	2631
	21st to end	Night	7% 9% 4 8% 6% 6% 5% 4 7% 8% 36%	2660
December	1st to 10th	Night	9% 12% 4 10% 7% 6% 5% 5% 6% 7% 29%	2660
	11th to 20th	Night	9% 13% 6% 13% 9% 6% 7% 6% 7% 6% 18%	3276
	21st to end	Night	9% 12% 4 13% 9% 7% 7% 4 6% 7% 21%	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	62% 13% 15% 9% 2	2539
	11th to 20th	Day	69% 8% 10% 8% 3 2	2540
	21st to end	Day	58% 12% 17% 10% 4 1	2900
February	1st to 10th	Day	52% 10% 15% 17% 6% 1	1710
	11th to 20th	Day	50% 8% 15% 19% 8% 1	1693
	21st to end	Day	52% 10% 17% 14% 7% 1	1570
March	1st to 10th	Day	45% 5% 15% 20% 14%	3138
	11th to 20th	Day	36% 7% 14% 30% 12%	3458
	21st to end	Day	50% 10% 17% 18% 5%	4036
April	1st to 10th	Day	51% 8% 12% 18% 11%	2280
	11th to 20th	Day	46% 6% 14% 17% 14% 3	2252
	21st to end	Day	38% 8% 14% 27% 11% 2	2370
May	1st to 10th	Day	35% 6% 13% 28% 18% 1	4420
	11th to 20th	Day	23% 4 10% 30% 30% 3	4380
	21st to end	Day	36% 7% 19% 27% 11% 1	4814
June	1st to 10th	Day	40% 6% 10% 27% 14% 3	2660
	11th to 20th	Day	31% 6% 11% 30% 19% 3	2660
	21st to end	Day	19% 4 10% 31% 27% 9%	2660
July	1st to 10th	Day	8% 1 5% 13% 24% 50%	4351
	11th to 20th	Day	9% 2 5% 7% 23% 54%	4345
	21st to end	Day	10% 2 6% 16% 36% 31%	4639
August	1st to 10th	Day	16% 2 5% 13% 38% 26%	4296
	11th to 20th	Day	14% 2 6% 33% 31% 14%	4017
	21st to end	Day	16% 3 7% 29% 28% 18%	4179
September	1st to 10th	Day	13% 3 8% 26% 31% 19%	2280
	11th to 20th	Day	25% 5% 10% 24% 24% 11%	2280
	21st to end	Day	28% 5% 12% 26% 22% 8%	2045
October	1st to 10th	Day	35% 5% 10% 22% 21% 6%	1900
	11th to 20th	Day	34% 7% 16% 23% 16% 3	1900
	21st to end	Day	42% 8% 13% 23% 13% 2	1958
November	1st to 10th	Day	47% 9% 12% 23% 8% 1	1674
	11th to 20th	Day	54% 10% 16% 15% 6%	1546
	21st to end	Day	47% 11% 15% 16% 9% 1	1520
December	1st to 10th	Day	51% 10% 13% 19% 7%	1520
	11th to 20th	Day	61% 10% 15% 12% 1	1928
	21st to end	Day	64% 10% 13% 11% 2	2794
January	1st to 10th	Night	65% 11% 13% 8% 2	4406
	11th to 20th	Night	66% 9% 10% 9% 4 1	4420
	21st to end	Night	59% 12% 15% 10% 4	4755
February	1st to 10th	Night	51% 9% 19% 15% 6%	2470
	11th to 20th	Night	47% 9% 16% 20% 8% 1	2385
	21st to end	Night	52% 10% 14% 16% 8% 1	1884
March	1st to 10th	Night	42% 7% 14% 24% 12% 1	3736
	11th to 20th	Night	31% 6% 18% 34% 11%	3521
	21st to end	Night	50% 13% 18% 15% 4	3617
April	1st to 10th	Night	45% 9% 16% 21% 8% 1	1900
	11th to 20th	Night	41% 8% 18% 21% 10% 2	1879
	21st to end	Night	38% 9% 15% 24% 11% 2	1806
May	1st to 10th	Night	35% 6% 14% 28% 17%	2540
	11th to 20th	Night	20% 5% 10% 39% 25% 1	2516
	21st to end	Night	29% 9% 30% 24% 7% 1	2762
June	1st to 10th	Night	35% 10% 12% 28% 14% 2	1520
	11th to 20th	Night	28% 7% 13% 36% 13% 4	1520
	21st to end	Night	19% 3 12% 33% 25% 7%	1520
July	1st to 10th	Night	6% 2 6% 15% 26% 44%	2500
	11th to 20th	Night	10% 2 5% 13% 19% 50%	2492
	21st to end	Night	8% 1 5% 20% 37% 29%	2674
August	1st to 10th	Night	15% 3 6% 16% 38% 23%	2609
	11th to 20th	Night	12% 3 8% 39% 28% 9%	2889
	21st to end	Night	12% 4 12% 29% 28% 16%	3498
September	1st to 10th	Night	11% 3 9% 28% 32% 17%	1900
	11th to 20th	Night	22% 6% 11% 26% 23% 13%	1900
	21st to end	Night	25% 5% 9% 28% 24% 9%	2132
October	1st to 10th	Night	30% 5% 11% 25% 25% 5%	2280
	11th to 20th	Night	32% 7% 15% 23% 19% 3	2280
	21st to end	Night	39% 8% 13% 21% 17% 2	2639
November	1st to 10th	Night	49% 7% 12% 21% 9% 1	2411
	11th to 20th	Night	52% 9% 15% 19% 5%	2631
	21st to end	Night	43% 10% 16% 20% 10% 1	2660
December	1st to 10th	Night	51% 11% 15% 17% 6%	2660
	11th to 20th	Night	59% 10% 16% 11% 3	3276
	21st to end	Night	58% 10% 16% 11% 4	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	26% 8% 22% 25% 12% 6%	180
	11th to 20th	Day	17% 13% 22% 28% 16% 4	180
	21st to end	Day	11% 14% 26% 27% 17% 5%	265
February	1st to 10th	Day	17% 17% 22% 25% 15% 4	370
	11th to 20th	Day	16% 17% 27% 24% 14% 2	374
	21st to end	Day	15% 17% 26% 26% 14% 2	382
March	1st to 10th	Day	16% 20% 25% 26% 12% 2	460
	11th to 20th	Day	15% 15% 23% 28% 14% 5%	460
	21st to end	Day	16% 18% 28% 27% 10% 1	506
April	1st to 10th	Day	18% 18% 23% 26% 11% 4	460
	11th to 20th	Day	15% 17% 31% 20% 12% 5%	452
	21st to end	Day	10% 23% 27% 23% 13% 4	460
May	1st to 10th	Day	11% 15% 28% 26% 15% 5%	463
	11th to 20th	Day	16% 12% 23% 29% 14% 6%	488
	21st to end	Day	13% 11% 19% 30% 19% 7%	529
June	1st to 10th	Day	10% 13% 25% 26% 17% 8%	490
	11th to 20th	Day	11% 19% 25% 27% 14% 4	490
	21st to end	Day	4 10% 22% 35% 21% 7%	490
July	1st to 10th	Day	2 7% 27% 36% 24% 5%	486
	11th to 20th	Day	2 10% 25% 32% 25% 7%	484
	21st to end	Day	2 5% 25% 31% 26% 11%	531
August	1st to 10th	Day	4 6% 25% 29% 24% 13%	487
	11th to 20th	Day	3 5% 18% 30% 27% 17%	477
	21st to end	Day	5% 7% 24% 29% 24% 10%	539
September	1st to 10th	Day	3 6% 22% 28% 27% 13%	490
	11th to 20th	Day	6% 8% 22% 30% 27% 6%	490
	21st to end	Day	11% 10% 16% 31% 26% 7%	490
October	1st to 10th	Day	10% 12% 21% 28% 20% 8%	490
	11th to 20th	Day	9% 14% 19% 26% 25% 7%	490
	21st to end	Day	13% 17% 25% 23% 16% 6%	407
November	1st to 10th	Day	11% 16% 24% 31% 14% 4	270
	11th to 20th	Day	9% 14% 26% 25% 19% 7%	192
	21st to end	Day	16% 12% 22% 24% 22% 5%	180
December	1st to 10th	Day	12% 11% 18% 28% 23% 9%	180
	11th to 20th	Day	18% 10% 24% 36% 9% 3	180
	21st to end	Day	18% 14% 20% 30% 15% 4	198
January	1st to 10th	Night	16% 11% 24% 31% 16% 2	760
	11th to 20th	Night	16% 11% 21% 28% 22% 3	760
	21st to end	Night	15% 9% 16% 38% 20% 2	836
February	1st to 10th	Night	16% 10% 23% 34% 16% 1	760
	11th to 20th	Night	13% 10% 25% 34% 17% 1	744
	21st to end	Night	16% 13% 24% 35% 11% 1	628
March	1st to 10th	Night	12% 10% 26% 37% 14% 1	760
	11th to 20th	Night	10% 10% 20% 41% 18% 2	760
	21st to end	Night	10% 11% 27% 37% 14% 1	836
April	1st to 10th	Night	13% 11% 22% 35% 18% 1	760
	11th to 20th	Night	10% 10% 28% 32% 16% 3	751
	21st to end	Night	10% 10% 24% 38% 17% 2	666
May	1st to 10th	Night	6% 7% 21% 42% 22% 2	380
	11th to 20th	Night	11% 6% 16% 38% 28% 2	374
	21st to end	Night	7% 8% 17% 37% 29% 2	411
June	1st to 10th	Night	11% 4 17% 44% 22% 1	380
	11th to 20th	Night	7% 6% 23% 46% 16% 2	380
	21st to end	Night	8% 3 11% 51% 26% 1	380
July	1st to 10th	Night	3 1 9% 54% 32% 2	370
	11th to 20th	Night	1 1 13% 59% 25% 2	368
	21st to end	Night	1 9% 54% 33% 2	416
August	1st to 10th	Night	2 1 6% 48% 40% 3	427
	11th to 20th	Night	3 1 7% 36% 45% 9%	588
	21st to end	Night	2 3 16% 44% 31% 4	836
September	1st to 10th	Night	2 3 14% 41% 35% 5%	760
	11th to 20th	Night	5% 3 11% 40% 35% 7%	760
	21st to end	Night	8% 4 14% 38% 31% 5%	760
October	1st to 10th	Night	8% 3 16% 42% 27% 4	760
	11th to 20th	Night	7% 7% 19% 37% 26% 5%	760
	21st to end	Night	12% 8% 20% 37% 17% 5%	836
November	1st to 10th	Night	14% 7% 23% 37% 18% 1	742
	11th to 20th	Night	15% 12% 21% 34% 17% 2	760
	21st to end	Night	11% 9% 20% 36% 19% 4	760
December	1st to 10th	Night	16% 7% 19% 36% 19% 3	760
	11th to 20th	Night	16% 11% 21% 36% 15% 1	760
	21st to end	Night	17% 13% 26% 32% 11% 1	836

Page generated at 2024-10-29 08:20:50. Version ac07

Copyright © 2024 Attilla Danko.