Deep South Regional Star Gaze
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Deep South Regional Star Gaze clear sky chart from 2005-11-06 to 2025-12-03.

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% 3 7% 5% 5% 5% 4 6% 8% 40%	125822
	Night	13% 7% 2 6% 4 4 4 3 5% 7% 44%	124991
Transparency	Day	25% 40% 7% 12% 11% 5%	129435
	Night	25% 39% 7% 12% 12% 6%	129453
Seeing	Day	15% 8% 20% 25% 21% 10%	16321
	Night	15% 8% 22% 29% 21% 5%	26013

By Month

Percentage Cloud Cover SE (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	17% 7% 3 7% 3 3 3 3 4 6% 43%	4077
	11th to 20th	Day	13% 7% 3 6% 4 4 3 2 3 4 52%	4080
	21st to end	Day	22% 10% 3 6% 4 4 4 3 4 4 35%	4559
February	1st to 10th	Day	17% 8% 3 7% 5% 4 4 4 4 5% 39%	2000
	11th to 20th	Day	19% 8% 3 5% 5% 4 4 3 5% 6% 40%	1948
	21st to end	Day	17% 9% 3 6% 5% 5% 4 4 6% 5% 36%	1650
March	1st to 10th	Day	20% 9% 3 7% 5% 4 4 3 5% 7% 33%	4887
	11th to 20th	Day	14% 6% 2 6% 5% 5% 4 4 5% 5% 43%	4980
	21st to end	Day	14% 8% 3 7% 5% 5% 4 3 4 5% 40%	5617
April	1st to 10th	Day	11% 7% 3 7% 5% 5% 5% 4 6% 6% 42%	2400
	11th to 20th	Day	15% 7% 3 7% 4 4 4 4 5% 7% 40%	2374
	21st to end	Day	9% 6% 2 7% 5% 5% 5% 5% 7% 7% 42%	2400
May	1st to 10th	Day	17% 7% 3 7% 5% 5% 6% 5% 6% 8% 31%	5405
	11th to 20th	Day	11% 5% 2 7% 5% 5% 5% 5% 7% 9% 40%	5404
	21st to end	Day	7% 5% 2 7% 6% 5% 6% 5% 8% 11% 39%	5932
June	1st to 10th	Day	8% 5% 3 8% 7% 7% 7% 6% 8% 10% 31%	2553
	11th to 20th	Day	6% 5% 2 8% 7% 8% 7% 7% 8% 9% 33%	2600
	21st to end	Day	7% 6% 3 7% 7% 8% 8% 7% 8% 10% 29%	2600
July	1st to 10th	Day	4 5% 3 9% 8% 8% 9% 7% 9% 11% 27%	5900
	11th to 20th	Day	6% 5% 2 7% 7% 8% 8% 6% 10% 11% 30%	5900
	21st to end	Day	8% 7% 3 9% 7% 6% 7% 6% 8% 11% 29%	6204
August	1st to 10th	Day	3 3 1 5% 4 5% 5% 4 6% 9% 54%	3905
	11th to 20th	Day	6% 4 1 6% 5% 6% 7% 6% 9% 10% 41%	3849
	21st to end	Day	10% 6% 3 8% 6% 7% 6% 5% 6% 7% 36%	4312
September	1st to 10th	Day	10% 5% 2 8% 5% 6% 7% 5% 8% 9% 35%	2400
	11th to 20th	Day	12% 6% 2 6% 5% 5% 4 4 6% 9% 39%	2390
	21st to end	Day	9% 6% 2 5% 4 4 5% 4 5% 6% 51%	2200
October	1st to 10th	Day	7% 3 2 5% 4 5% 4 3 6% 7% 54%	2001
	11th to 20th	Day	9% 4 1 4 4 3 4 3 4 6% 58%	2000
	21st to end	Day	10% 5% 2 5% 4 3 3 2 4 5% 57%	2200
November	1st to 10th	Day	10% 6% 1 6% 3 4 4 4 4 5% 53%	2058
	11th to 20th	Day	10% 5% 2 7% 4 4 4 3 5% 5% 52%	2100
	21st to end	Day	13% 7% 3 5% 4 4 5% 3 5% 6% 45%	1915
December	1st to 10th	Day	16% 8% 3 6% 4 4 4 3 4 5% 41%	2948
	11th to 20th	Day	12% 7% 3 6% 5% 4 5% 3 5% 6% 44%	3586
	21st to end	Day	16% 8% 2 6% 3 3 3 3 5% 5% 46%	4488
January	1st to 10th	Night	20% 6% 2 4 2 3 3 3 4 5% 48%	5888
	11th to 20th	Night	18% 8% 3 5% 3 3 3 2 3 5% 47%	5900
	21st to end	Night	26% 8% 2 5% 3 3 3 3 4 6% 37%	6398
February	1st to 10th	Night	16% 8% 3 6% 5% 4 4 3 4 6% 42%	2400
	11th to 20th	Night	22% 7% 3 5% 3 3 3 3 5% 6% 40%	2338
	21st to end	Night	21% 8% 3 6% 3 3 4 3 5% 6% 37%	1980
March	1st to 10th	Night	19% 11% 3 6% 3 3 3 3 5% 7% 37%	5007
	11th to 20th	Night	15% 7% 2 6% 4 4 4 3 4 6% 45%	4980
	21st to end	Night	19% 7% 2 6% 4 4 4 3 4 5% 42%	5296
April	1st to 10th	Night	13% 7% 2 6% 4 4 4 3 6% 8% 43%	2000
	11th to 20th	Night	14% 6% 3 6% 4 4 3 3 5% 7% 47%	1975
	21st to end	Night	10% 5% 2 4 4 4 4 4 5% 7% 53%	2000
May	1st to 10th	Night	17% 7% 3 8% 4 4 4 3 6% 8% 38%	4490
	11th to 20th	Night	15% 7% 2 6% 3 4 4 4 5% 8% 42%	4489
	21st to end	Night	10% 6% 2 6% 5% 5% 5% 5% 8% 11% 38%	4922
June	1st to 10th	Night	7% 5% 2 7% 4 4 5% 5% 8% 10% 43%	1840
	11th to 20th	Night	3 5% 2 5% 4 5% 6% 5% 8% 11% 46%	1800
	21st to end	Night	5% 5% 3 6% 6% 6% 7% 6% 9% 12% 37%	1800
July	1st to 10th	Night	4 5% 2 9% 6% 7% 8% 6% 9% 12% 33%	4078
	11th to 20th	Night	4 4 2 6% 5% 6% 7% 5% 10% 13% 39%	4077
	21st to end	Night	5% 6% 2 8% 6% 6% 7% 6% 8% 12% 33%	4657
August	1st to 10th	Night	2 2 1 4 3 3 4 3 7% 11% 60%	3244
	11th to 20th	Night	3 3 2 6% 5% 6% 6% 4 8% 13% 45%	3200
	21st to end	Night	7% 6% 3 8% 5% 5% 5% 4 6% 8% 42%	3586
September	1st to 10th	Night	8% 5% 2 6% 4 5% 6% 4 8% 10% 42%	2000
	11th to 20th	Night	9% 6% 2 6% 4 5% 5% 4 7% 8% 45%	2000
	21st to end	Night	8% 4 2 5% 4 4 4 4 5% 7% 52%	2189
October	1st to 10th	Night	7% 5% 2 4 3 3 3 3 5% 6% 59%	2392
	11th to 20th	Night	7% 5% 2 5% 3 3 3 3 4 5% 60%	2400
	21st to end	Night	11% 5% 2 5% 3 3 3 2 5% 6% 57%	2640
November	1st to 10th	Night	11% 5% 2 5% 4 3 4 3 4 5% 55%	2460
	11th to 20th	Night	12% 5% 2 4 3 3 3 3 4 5% 56%	2520
	21st to end	Night	14% 6% 2 6% 3 3 4 3 5% 6% 48%	2696
December	1st to 10th	Night	20% 7% 2 5% 4 4 3 2 3 5% 44%	4277
	11th to 20th	Night	13% 10% 3 7% 4 4 4 3 5% 5% 44%	4582
	21st to end	Night	20% 10% 2 5% 3 3 2 2 3 4 45%	6490

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	32% 27% 3 16% 19% 2	4078
	11th to 20th	Day	27% 26% 3 13% 23% 8%	4080
	21st to end	Day	40% 28% 4 7% 11% 10%	4559
February	1st to 10th	Day	19% 62% 2 5% 6% 5%	2000
	11th to 20th	Day	20% 60% 3 7% 8% 2	1958
	21st to end	Day	21% 62% 3 3 6% 5%	1650
March	1st to 10th	Day	39% 30% 5% 8% 12% 7%	4887
	11th to 20th	Day	29% 30% 4 10% 11% 16%	4980
	21st to end	Day	35% 30% 6% 10% 13% 6%	5619
April	1st to 10th	Day	17% 62% 2 7% 8% 4	2400
	11th to 20th	Day	19% 62% 4 6% 6% 4	2374
	21st to end	Day	15% 62% 5% 8% 7% 3	2400
May	1st to 10th	Day	36% 33% 8% 16% 6% 2	5440
	11th to 20th	Day	27% 31% 11% 16% 13% 1	5408
	21st to end	Day	24% 32% 11% 21% 10% 2	5945
June	1st to 10th	Day	17% 64% 4 8% 7% 1	2553
	11th to 20th	Day	21% 63% 6% 6% 4	2600
	21st to end	Day	18% 63% 8% 8% 3	2600
July	1st to 10th	Day	29% 35% 18% 14% 5%	5836
	11th to 20th	Day	28% 36% 24% 12% 1	5831
	21st to end	Day	33% 31% 11% 20% 4	6026
August	1st to 10th	Day	10% 36% 8% 24% 21% 1	3893
	11th to 20th	Day	15% 40% 14% 21% 8%	3885
	21st to end	Day	28% 39% 9% 10% 13% 1	4311
September	1st to 10th	Day	17% 58% 8% 9% 6% 2	2400
	11th to 20th	Day	13% 57% 6% 12% 9% 2	2390
	21st to end	Day	14% 58% 6% 13% 7% 3	2200
October	1st to 10th	Day	14% 36% 4 7% 13% 26%	3261
	11th to 20th	Day	7% 35% 4 12% 17% 26%	3240
	21st to end	Day	13% 35% 2 7% 28% 14%	3538
November	1st to 10th	Day	19% 54% 4 10% 9% 5%	2058
	11th to 20th	Day	18% 54% 3 8% 11% 6%	2100
	21st to end	Day	17% 55% 4 9% 11% 4	1915
December	1st to 10th	Day	32% 35% 3 8% 17% 4	2948
	11th to 20th	Day	24% 33% 7% 9% 18% 9%	3584
	21st to end	Day	31% 27% 4 15% 20% 3	4488
January	1st to 10th	Night	30% 27% 4 17% 18% 5%	5888
	11th to 20th	Night	30% 26% 4 10% 22% 8%	5900
	21st to end	Night	38% 28% 4 10% 13% 8%	6398
February	1st to 10th	Night	17% 61% 2 7% 8% 4	2400
	11th to 20th	Night	19% 61% 2 8% 8% 3	2339
	21st to end	Night	19% 61% 3 6% 5% 5%	1980
March	1st to 10th	Night	38% 30% 5% 6% 14% 6%	5007
	11th to 20th	Night	28% 31% 4 10% 12% 15%	4980
	21st to end	Night	34% 30% 5% 13% 12% 6%	5296
April	1st to 10th	Night	17% 62% 3 6% 8% 4	2000
	11th to 20th	Night	16% 62% 4 8% 7% 3	1975
	21st to end	Night	14% 63% 4 9% 8% 3	2000
May	1st to 10th	Night	34% 33% 9% 12% 10% 2	4520
	11th to 20th	Night	30% 31% 12% 17% 9% 1	4490
	21st to end	Night	28% 32% 12% 20% 7% 1	4931
June	1st to 10th	Night	12% 63% 6% 10% 7% 1	1840
	11th to 20th	Night	14% 64% 8% 9% 3 1	1800
	21st to end	Night	16% 63% 10% 8% 3	1800
July	1st to 10th	Night	28% 35% 20% 13% 4	4035
	11th to 20th	Night	24% 36% 30% 9% 1	4026
	21st to end	Night	31% 34% 12% 19% 3	4522
August	1st to 10th	Night	9% 37% 10% 23% 21% 1	3232
	11th to 20th	Night	16% 41% 15% 23% 5% 1	3230
	21st to end	Night	26% 39% 8% 12% 11% 3	3586
September	1st to 10th	Night	14% 59% 9% 9% 7% 3	2000
	11th to 20th	Night	11% 59% 8% 12% 7% 3	2000
	21st to end	Night	14% 58% 7% 12% 6% 3	2189
October	1st to 10th	Night	14% 36% 5% 8% 13% 23%	3912
	11th to 20th	Night	7% 35% 2 14% 18% 24%	3899
	21st to end	Night	12% 35% 3 6% 27% 16%	4252
November	1st to 10th	Night	20% 53% 5% 8% 9% 4	2460
	11th to 20th	Night	17% 54% 3 8% 12% 7%	2520
	21st to end	Night	17% 54% 3 9% 11% 5%	2696
December	1st to 10th	Night	33% 34% 2 10% 19% 2	4277
	11th to 20th	Night	27% 32% 6% 12% 15% 9%	4583
	21st to end	Night	33% 27% 4 13% 17% 6%	6490

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% 22% 32% 14% 5% 1	300
	11th to 20th	Day	26% 16% 37% 15% 5%	300
	21st to end	Day	31% 19% 37% 11% 2	330
February	1st to 10th	Day	29% 19% 35% 13% 3 1	300
	11th to 20th	Day	38% 17% 29% 11% 4	300
	21st to end	Day	25% 25% 39% 10% 2	249
March	1st to 10th	Day	26% 20% 35% 16% 3	300
	11th to 20th	Day	28% 20% 36% 13% 2	300
	21st to end	Day	19% 22% 33% 20% 5% 1	395
April	1st to 10th	Day	20% 15% 34% 21% 9% 1	500
	11th to 20th	Day	25% 14% 29% 21% 9% 2	492
	21st to end	Day	13% 10% 29% 32% 13% 3	500
May	1st to 10th	Day	19% 8% 27% 31% 12% 2	503
	11th to 20th	Day	15% 6% 26% 26% 19% 8%	527
	21st to end	Day	7% 6% 21% 34% 21% 11%	573
June	1st to 10th	Day	11% 3 13% 34% 27% 11%	683
	11th to 20th	Day	7% 3 14% 37% 28% 10%	730
	21st to end	Day	9% 5% 11% 26% 32% 18%	730
July	1st to 10th	Day	8% 3 6% 27% 37% 20%	721
	11th to 20th	Day	6% 2 4 25% 41% 22%	718
	21st to end	Day	10% 4 5% 24% 41% 16%	702
August	1st to 10th	Day	6% 2 4 20% 40% 28%	526
	11th to 20th	Day	8% 2 3 14% 42% 30%	519
	21st to end	Day	12% 2 6% 24% 31% 24%	583
September	1st to 10th	Day	12% 3 8% 28% 32% 18%	530
	11th to 20th	Day	11% 4 11% 24% 36% 15%	530
	21st to end	Day	11% 3 10% 32% 32% 12%	530
October	1st to 10th	Day	7% 5% 25% 39% 18% 6%	331
	11th to 20th	Day	11% 5% 23% 34% 22% 6%	330
	21st to end	Day	19% 10% 23% 30% 13% 5%	363
November	1st to 10th	Day	15% 8% 31% 32% 12% 3	330
	11th to 20th	Day	16% 8% 36% 26% 12% 2	330
	21st to end	Day	18% 15% 35% 21% 7% 3	330
December	1st to 10th	Day	24% 12% 36% 19% 8% 1	306
	11th to 20th	Day	21% 15% 38% 21% 5% 1	300
	21st to end	Day	28% 14% 34% 19% 5% 1	330
January	1st to 10th	Night	24% 14% 33% 24% 6%	1000
	11th to 20th	Night	23% 13% 32% 25% 7% 1	1000
	21st to end	Night	25% 13% 33% 24% 5%	1060
February	1st to 10th	Night	21% 15% 35% 25% 4	800
	11th to 20th	Night	28% 15% 27% 24% 5%	783
	21st to end	Night	27% 17% 32% 21% 3	660
March	1st to 10th	Night	21% 13% 33% 28% 5%	640
	11th to 20th	Night	20% 11% 34% 28% 7%	600
	21st to end	Night	18% 10% 37% 28% 7%	660
April	1st to 10th	Night	18% 13% 33% 26% 10% 1	600
	11th to 20th	Night	17% 9% 35% 26% 12% 1	593
	21st to end	Night	12% 8% 31% 34% 15% 1	600
May	1st to 10th	Night	12% 5% 29% 39% 15% 1	600
	11th to 20th	Night	14% 3 24% 37% 22% 2	591
	21st to end	Night	7% 3 18% 38% 28% 6%	650
June	1st to 10th	Night	9% 3 11% 38% 34% 6%	600
	11th to 20th	Night	3 1 10% 35% 42% 9%	600
	21st to end	Night	7% 1 8% 28% 40% 16%	600
July	1st to 10th	Night	4 2 4 25% 46% 18%	585
	11th to 20th	Night	5% 2 3 21% 47% 21%	582
	21st to end	Night	6% 2 4 24% 49% 15%	657
August	1st to 10th	Night	4 2 2 21% 51% 20%	597
	11th to 20th	Night	5% 1 4 20% 49% 20%	594
	21st to end	Night	9% 2 5% 23% 42% 18%	660
September	1st to 10th	Night	8% 3 7% 26% 43% 14%	600
	11th to 20th	Night	11% 3 7% 30% 41% 9%	600
	21st to end	Night	10% 4 10% 32% 38% 6%	789
October	1st to 10th	Night	8% 3 18% 36% 32% 4	800
	11th to 20th	Night	10% 4 23% 36% 23% 4	800
	21st to end	Night	15% 8% 21% 34% 20% 2	880
November	1st to 10th	Night	14% 7% 20% 35% 22% 2	820
	11th to 20th	Night	15% 7% 29% 35% 14% 2	840
	21st to end	Night	17% 10% 30% 28% 13% 1	840
December	1st to 10th	Night	21% 11% 28% 29% 10%	809
	11th to 20th	Night	24% 8% 32% 29% 7%	823
	21st to end	Night	28% 11% 29% 25% 7%	1100

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