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 2024-03-01.

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	7% 8% 3 7% 6% 3 5% 5% 5% 7% 44%	78404
	Night	8% 8% 4 7% 7% 4 5% 5% 6% 7% 40%	81028
Transparency	Day	39% 7% 12% 20% 16% 7%	78107
	Night	42% 8% 14% 19% 13% 4	80846
Seeing	Day	11% 13% 24% 28% 19% 6%	13588
	Night	11% 8% 19% 38% 22% 3	22820

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% 11% 5% 13% 10% 6% 8% 7% 7% 8% 14%	2539
	11th to 20th	Day	13% 16% 7% 12% 9% 4 6% 6% 4 4 19%	2540
	21st to end	Day	10% 13% 6% 9% 8% 4 7% 8% 7% 9% 20%	2900
February	1st to 10th	Day	9% 13% 3 9% 7% 4 6% 6% 6% 9% 29%	1710
	11th to 20th	Day	10% 10% 5% 9% 7% 4 4 6% 7% 8% 31%	1684
	21st to end	Day	8% 11% 5% 8% 9% 5% 7% 7% 7% 7% 27%	1570
March	1st to 10th	Day	8% 13% 5% 10% 8% 4 6% 7% 6% 8% 26%	1801
	11th to 20th	Day	8% 12% 5% 9% 8% 4 7% 5% 6% 8% 27%	1961
	21st to end	Day	9% 11% 6% 9% 8% 4 7% 7% 7% 8% 24%	2299
April	1st to 10th	Day	10% 11% 4 8% 7% 5% 6% 6% 6% 7% 29%	2160
	11th to 20th	Day	9% 10% 5% 8% 7% 3 6% 5% 4 6% 37%	2129
	21st to end	Day	7% 7% 3 6% 5% 4 6% 5% 7% 7% 42%	2244
May	1st to 10th	Day	7% 6% 3 5% 6% 3 5% 5% 6% 7% 47%	2520
	11th to 20th	Day	9% 7% 3 7% 6% 4 5% 5% 6% 8% 42%	2477
	21st to end	Day	12% 7% 3 6% 6% 3 4 4 7% 8% 40%	2723
June	1st to 10th	Day	10% 7% 3 6% 6% 3 4 5% 5% 7% 43%	2520
	11th to 20th	Day	8% 5% 3 5% 4 3 5% 5% 5% 7% 51%	2520
	21st to end	Day	4 2 2 3 3 2 3 3 4 5% 68%	2520
July	1st to 10th	Day	2 2 1 3 2 1 3 3 4 5% 74%	2520
	11th to 20th	Day	3 2 1 2 2 2 3 3 3 5% 74%	2520
	21st to end	Day	2 1 1 1 1 1 2 2 3 4 82%	2741
August	1st to 10th	Day	2 2 1 2 3 2 3 3 4 5% 73%	2458
	11th to 20th	Day	2 2 1 2 3 1 2 2 3 6% 76%	2276
	21st to end	Day	2 3 1 2 1 2 2 2 3 6% 75%	2376
September	1st to 10th	Day	2 2 1 2 2 2 2 3 3 5% 76%	2160
	11th to 20th	Day	4 4 2 4 4 2 4 5% 5% 7% 59%	2160
	21st to end	Day	9% 4 1 4 5% 3 3 4 4 6% 56%	1939
October	1st to 10th	Day	9% 8% 3 6% 5% 3 4 4 5% 5% 49%	1800
	11th to 20th	Day	7% 5% 3 5% 6% 3 5% 5% 5% 9% 46%	1800
	21st to end	Day	9% 9% 3 8% 5% 4 6% 5% 5% 7% 40%	1855
November	1st to 10th	Day	11% 8% 4 8% 7% 5% 6% 6% 8% 8% 30%	1674
	11th to 20th	Day	9% 10% 5% 9% 9% 5% 7% 6% 7% 8% 24%	1546
	21st to end	Day	8% 10% 5% 8% 7% 5% 6% 7% 6% 9% 31%	1520
December	1st to 10th	Day	8% 9% 6% 8% 9% 5% 7% 6% 5% 7% 31%	1520
	11th to 20th	Day	9% 11% 6% 13% 11% 5% 7% 6% 8% 7% 17%	1928
	21st to end	Day	11% 14% 6% 11% 9% 6% 7% 8% 7% 6% 15%	2794
January	1st to 10th	Night	8% 11% 6% 13% 13% 6% 8% 7% 7% 6% 15%	4406
	11th to 20th	Night	15% 15% 6% 10% 8% 4 5% 6% 5% 7% 19%	4420
	21st to end	Night	10% 13% 5% 11% 9% 5% 6% 6% 7% 8% 20%	4755
February	1st to 10th	Night	9% 11% 5% 9% 8% 4 5% 5% 6% 7% 29%	2470
	11th to 20th	Night	9% 10% 4 8% 7% 4 5% 5% 6% 7% 35%	2383
	21st to end	Night	10% 11% 5% 8% 7% 4 7% 6% 6% 8% 28%	1884
March	1st to 10th	Night	9% 10% 4 9% 8% 5% 7% 5% 7% 8% 29%	2165
	11th to 20th	Night	7% 9% 5% 9% 8% 5% 6% 6% 7% 11% 28%	1998
	21st to end	Night	6% 11% 5% 8% 8% 5% 8% 7% 6% 9% 27%	2057
April	1st to 10th	Night	9% 9% 4 8% 7% 3 5% 6% 6% 9% 34%	1800
	11th to 20th	Night	7% 9% 5% 6% 7% 3 5% 5% 6% 7% 40%	1779
	21st to end	Night	7% 7% 3 6% 6% 4 5% 6% 6% 7% 41%	1712
May	1st to 10th	Night	5% 6% 3 5% 5% 3 4 5% 7% 7% 50%	1440
	11th to 20th	Night	9% 5% 3 5% 4 3 5% 6% 6% 10% 45%	1416
	21st to end	Night	8% 6% 3 5% 5% 3 5% 5% 6% 9% 45%	1552
June	1st to 10th	Night	9% 6% 3 5% 4 3 4 5% 6% 7% 47%	1440
	11th to 20th	Night	6% 5% 2 5% 4 2 4 5% 6% 8% 54%	1440
	21st to end	Night	5% 4 1 3 2 2 2 4 4 5% 68%	1440
July	1st to 10th	Night	2 1 1 2 2 2 3 3 4 5% 76%	1440
	11th to 20th	Night	1 1 1 1 2 2 3 3 3 5% 78%	1440
	21st to end	Night	1 1 1 2 1 2 2 3 3 82%	1576
August	1st to 10th	Night	2 2 1 2 3 2 2 3 4 6% 74%	1478
	11th to 20th	Night	2 1 1 2 3 2 3 3 3 5% 75%	1624
	21st to end	Night	2 2 1 2 2 2 2 3 3 5% 75%	1980
September	1st to 10th	Night	2 2 1 2 1 1 2 3 3 5% 78%	1800
	11th to 20th	Night	5% 3 1 3 3 2 5% 4 4 7% 63%	1800
	21st to end	Night	6% 4 2 4 4 2 4 4 5% 7% 59%	2019
October	1st to 10th	Night	8% 6% 2 5% 4 2 3 3 4 6% 55%	2160
	11th to 20th	Night	7% 6% 2 5% 6% 3 4 5% 6% 8% 49%	2160
	21st to end	Night	8% 7% 3 6% 6% 4 5% 4 5% 6% 45%	2500
November	1st to 10th	Night	11% 9% 4 8% 7% 4 5% 6% 6% 7% 33%	2405
	11th to 20th	Night	10% 9% 5% 10% 7% 4 6% 7% 6% 8% 27%	2631
	21st to end	Night	7% 9% 4 8% 7% 4 6% 5% 7% 8% 36%	2660
December	1st to 10th	Night	10% 11% 5% 9% 8% 4 6% 6% 6% 7% 30%	2660
	11th to 20th	Night	9% 13% 6% 11% 10% 5% 7% 7% 7% 7% 18%	3276
	21st to end	Night	9% 12% 5% 11% 11% 5% 7% 6% 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	53% 7% 15% 16% 8% 1	1801
	11th to 20th	Day	53% 8% 12% 21% 5%	1961
	21st to end	Day	55% 9% 15% 16% 5%	2299
April	1st to 10th	Day	52% 7% 12% 18% 11% 1	2160
	11th to 20th	Day	46% 6% 14% 17% 13% 3	2132
	21st to end	Day	38% 7% 14% 27% 12% 2	2244
May	1st to 10th	Day	34% 6% 12% 29% 17% 1	2520
	11th to 20th	Day	39% 6% 13% 26% 15% 2	2480
	21st to end	Day	41% 6% 13% 25% 13% 1	2724
June	1st to 10th	Day	40% 6% 11% 28% 14% 2	2520
	11th to 20th	Day	32% 6% 12% 30% 17% 3	2520
	21st to end	Day	19% 4 10% 31% 27% 9%	2520
July	1st to 10th	Day	13% 3 8% 22% 31% 24%	2451
	11th to 20th	Day	13% 3 8% 13% 32% 31%	2445
	21st to end	Day	10% 1 4 14% 38% 32%	2589
August	1st to 10th	Day	14% 3 8% 22% 34% 19%	2441
	11th to 20th	Day	12% 2 6% 24% 34% 21%	2276
	21st to end	Day	12% 3 6% 29% 36% 14%	2376
September	1st to 10th	Day	13% 3 8% 27% 31% 19%	2160
	11th to 20th	Day	25% 5% 10% 23% 25% 11%	2160
	21st to end	Day	29% 5% 12% 25% 21% 8%	1939
October	1st to 10th	Day	37% 5% 10% 22% 20% 6%	1800
	11th to 20th	Day	34% 7% 15% 24% 16% 3	1800
	21st to end	Day	42% 8% 13% 23% 13% 2	1855
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% 13% 16% 8% 1	1884
March	1st to 10th	Night	50% 9% 13% 18% 9% 1	2165
	11th to 20th	Night	47% 8% 17% 23% 5%	1998
	21st to end	Night	49% 11% 18% 17% 4	2057
April	1st to 10th	Night	46% 9% 15% 21% 9% 1	1800
	11th to 20th	Night	42% 7% 17% 21% 10% 2	1779
	21st to end	Night	39% 9% 15% 23% 11% 3	1712
May	1st to 10th	Night	32% 7% 15% 30% 15% 1	1440
	11th to 20th	Night	34% 8% 17% 27% 13% 2	1416
	21st to end	Night	34% 10% 19% 24% 12% 1	1552
June	1st to 10th	Night	35% 10% 13% 28% 14% 1	1440
	11th to 20th	Night	28% 8% 13% 35% 12% 3	1440
	21st to end	Night	20% 4 12% 34% 24% 7%	1440
July	1st to 10th	Night	11% 4 11% 27% 26% 21%	1400
	11th to 20th	Night	10% 3 8% 19% 30% 29%	1392
	21st to end	Night	8% 1 5% 18% 41% 27%	1488
August	1st to 10th	Night	12% 3 9% 24% 34% 17%	1470
	11th to 20th	Night	13% 3 8% 23% 36% 17%	1624
	21st to end	Night	12% 4 8% 27% 38% 12%	1980
September	1st to 10th	Night	10% 3 9% 29% 32% 17%	1800
	11th to 20th	Night	21% 6% 10% 25% 24% 14%	1800
	21st to end	Night	26% 5% 9% 27% 24% 9%	2019
October	1st to 10th	Night	31% 5% 12% 25% 23% 5%	2160
	11th to 20th	Night	32% 7% 15% 23% 19% 4	2160
	21st to end	Night	39% 9% 13% 20% 17% 2	2500
November	1st to 10th	Night	49% 7% 12% 21% 10% 1	2405
	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% 27% 25% 14% 2	382
March	1st to 10th	Day	16% 20% 25% 26% 11% 2	421
	11th to 20th	Day	17% 15% 23% 28% 14% 3	420
	21st to end	Day	17% 18% 27% 27% 11% 1	462
April	1st to 10th	Day	20% 17% 22% 26% 11% 4	420
	11th to 20th	Day	17% 16% 31% 20% 12% 5%	412
	21st to end	Day	10% 23% 27% 22% 13% 4	420
May	1st to 10th	Day	10% 15% 27% 27% 16% 5%	423
	11th to 20th	Day	17% 12% 23% 29% 13% 6%	448
	21st to end	Day	13% 11% 20% 31% 19% 6%	485
June	1st to 10th	Day	10% 14% 25% 26% 17% 8%	450
	11th to 20th	Day	10% 19% 25% 28% 14% 4	450
	21st to end	Day	4 10% 22% 36% 21% 7%	450
July	1st to 10th	Day	2 7% 27% 36% 23% 5%	446
	11th to 20th	Day	2 9% 25% 32% 24% 7%	444
	21st to end	Day	2 4 25% 31% 26% 11%	487
August	1st to 10th	Day	3 6% 24% 30% 24% 13%	447
	11th to 20th	Day	3 4 18% 30% 27% 18%	437
	21st to end	Day	5% 7% 24% 28% 25% 10%	495
September	1st to 10th	Day	3 6% 23% 28% 28% 12%	450
	11th to 20th	Day	6% 8% 22% 30% 28% 6%	450
	21st to end	Day	11% 10% 17% 30% 25% 7%	450
October	1st to 10th	Day	11% 12% 21% 27% 21% 8%	450
	11th to 20th	Day	10% 15% 18% 24% 25% 8%	450
	21st to end	Day	13% 16% 24% 23% 17% 7%	370
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	13% 10% 25% 37% 14% 1	722
	11th to 20th	Night	10% 10% 20% 41% 18% 1	720
	21st to end	Night	10% 11% 26% 37% 15% 1	792
April	1st to 10th	Night	13% 11% 21% 36% 18% 2	720
	11th to 20th	Night	10% 10% 27% 32% 17% 3	711
	21st to end	Night	10% 10% 24% 37% 17% 2	632
May	1st to 10th	Night	5% 8% 19% 43% 23% 2	360
	11th to 20th	Night	11% 6% 15% 38% 29% 2	354
	21st to end	Night	7% 7% 18% 36% 29% 3	389
June	1st to 10th	Night	11% 4 16% 44% 23% 1	360
	11th to 20th	Night	7% 6% 23% 46% 16% 2	360
	21st to end	Night	8% 3 11% 50% 27% 1	360
July	1st to 10th	Night	3 1 9% 53% 33% 2	350
	11th to 20th	Night	1 1 14% 59% 24% 2	348
	21st to end	Night	1 9% 54% 34% 3	394
August	1st to 10th	Night	2 1 6% 46% 41% 3	404
	11th to 20th	Night	3 7% 34% 47% 9%	556
	21st to end	Night	2 3 16% 44% 31% 4	792
September	1st to 10th	Night	2 3 14% 41% 35% 4	720
	11th to 20th	Night	5% 3 10% 38% 37% 7%	720
	21st to end	Night	8% 4 13% 38% 31% 5%	720
October	1st to 10th	Night	9% 3 17% 41% 26% 4	720
	11th to 20th	Night	8% 7% 19% 36% 26% 5%	720
	21st to end	Night	13% 8% 20% 36% 18% 5%	792
November	1st to 10th	Night	14% 7% 23% 37% 18% 1	740
	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 2024-02-27 03:30:17. Version ac07

Copyright © 2024 Attilla Danko.