Dallas(GA)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Dallas(GA) clear sky chart from 2005-11-06 to 2024-11-04.

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	12% 7% 2 6% 5% 5% 5% 4 6% 8% 40%	100931
	Night	13% 7% 2 6% 4 4 4 4 6% 7% 44%	98037
Transparency	Day	40% 6% 11% 20% 19% 5%	104762
	Night	37% 5% 10% 20% 21% 6%	102344
Seeing	Day	17% 10% 23% 23% 18% 9%	14804
	Night	16% 10% 23% 28% 20% 4	24798

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	16% 11% 4 6% 3 4 4 3 5% 6% 37%	2836
	11th to 20th	Day	12% 7% 2 5% 4 4 4 3 4 6% 49%	2840
	21st to end	Day	23% 12% 2 5% 3 3 3 2 4 5% 38%	3321
February	1st to 10th	Day	17% 10% 2 6% 4 4 5% 3 5% 6% 38%	1900
	11th to 20th	Day	19% 8% 3 6% 3 4 3 3 4 6% 40%	1848
	21st to end	Day	20% 8% 3 6% 4 3 3 4 4 5% 39%	1570
March	1st to 10th	Day	23% 11% 3 7% 4 3 3 3 5% 5% 33%	3169
	11th to 20th	Day	13% 7% 2 6% 4 3 4 3 6% 6% 45%	3480
	21st to end	Day	16% 6% 3 7% 4 4 4 4 5% 6% 39%	3815
April	1st to 10th	Day	11% 7% 2 7% 4 5% 4 4 5% 6% 44%	2199
	11th to 20th	Day	12% 7% 2 6% 5% 4 4 3 5% 6% 47%	2254
	21st to end	Day	10% 4 1 5% 5% 4 4 4 5% 7% 50%	2392
May	1st to 10th	Day	9% 6% 3 6% 5% 5% 5% 4 6% 8% 43%	4082
	11th to 20th	Day	16% 8% 3 6% 4 5% 5% 5% 6% 7% 34%	4081
	21st to end	Day	8% 5% 2 6% 5% 4 5% 4 7% 10% 44%	4476
June	1st to 10th	Day	10% 7% 2 8% 6% 6% 6% 5% 7% 8% 34%	2470
	11th to 20th	Day	5% 4 2 5% 5% 5% 8% 6% 8% 11% 43%	2470
	21st to end	Day	7% 5% 2 7% 6% 6% 6% 6% 8% 9% 38%	2470
July	1st to 10th	Day	8% 6% 2 8% 8% 8% 8% 7% 9% 11% 25%	4120
	11th to 20th	Day	8% 5% 3 8% 7% 7% 7% 5% 8% 10% 32%	4120
	21st to end	Day	10% 9% 3 11% 9% 8% 8% 6% 8% 9% 19%	4466
August	1st to 10th	Day	5% 5% 2 6% 5% 5% 7% 6% 9% 12% 39%	4056
	11th to 20th	Day	7% 5% 2 5% 5% 6% 5% 4 7% 11% 43%	3729
	21st to end	Day	8% 5% 2 5% 5% 5% 6% 5% 6% 7% 48%	4180
September	1st to 10th	Day	12% 6% 2 6% 4 5% 5% 5% 7% 9% 39%	2128
	11th to 20th	Day	17% 6% 2 6% 4 4 4 3 6% 7% 40%	2090
	21st to end	Day	13% 6% 2 5% 4 3 4 4 4 6% 47%	2090
October	1st to 10th	Day	12% 5% 2 4 3 4 3 3 5% 5% 54%	2090
	11th to 20th	Day	11% 6% 1 4 3 3 3 2 4 7% 55%	2021
	21st to end	Day	14% 5% 2 5% 3 3 3 3 4 5% 55%	2062
November	1st to 10th	Day	13% 6% 2 4 4 3 2 3 4 4 55%	1699
	11th to 20th	Day	12% 6% 2 5% 4 3 4 3 5% 5% 52%	1710
	21st to end	Day	13% 7% 2 5% 4 4 4 4 5% 7% 45%	1710
December	1st to 10th	Day	18% 8% 2 7% 4 4 4 3 5% 6% 38%	1710
	11th to 20th	Day	17% 8% 3 6% 4 4 4 3 4 5% 42%	2153
	21st to end	Day	20% 8% 4 6% 3 4 4 3 5% 6% 36%	3124
January	1st to 10th	Night	17% 11% 3 5% 3 3 3 3 5% 6% 40%	4109
	11th to 20th	Night	12% 9% 3 6% 4 3 4 3 4 5% 45%	4120
	21st to end	Night	21% 14% 3 6% 3 2 2 2 4 4 39%	4331
February	1st to 10th	Night	14% 8% 3 6% 5% 5% 3 4 4 6% 42%	2280
	11th to 20th	Night	21% 8% 2 5% 4 3 4 3 4 5% 41%	2218
	21st to end	Night	19% 8% 2 7% 4 3 4 3 6% 5% 39%	1884
March	1st to 10th	Night	22% 11% 3 6% 4 3 4 3 4 6% 33%	3683
	11th to 20th	Night	11% 6% 1 4 4 3 4 4 6% 8% 49%	3480
	21st to end	Night	15% 7% 2 6% 4 4 5% 3 5% 6% 42%	3817
April	1st to 10th	Night	11% 5% 2 5% 4 5% 5% 4 6% 7% 46%	1995
	11th to 20th	Night	14% 5% 2 4 4 3 4 3 5% 7% 49%	1875
	21st to end	Night	9% 5% 1 5% 4 3 4 4 6% 7% 52%	1786
May	1st to 10th	Night	9% 6% 2 6% 5% 4 5% 4 6% 10% 42%	2813
	11th to 20th	Night	14% 7% 2 6% 5% 5% 5% 4 6% 8% 39%	2812
	21st to end	Night	7% 4 1 5% 4 4 5% 4 8% 11% 47%	3079
June	1st to 10th	Night	5% 6% 2 6% 6% 5% 5% 5% 9% 11% 38%	1710
	11th to 20th	Night	4 3 1 4 5% 4 6% 5% 7% 12% 48%	1710
	21st to end	Night	6% 4 1 5% 5% 4 5% 5% 8% 13% 44%	1710
July	1st to 10th	Night	8% 6% 3 9% 7% 6% 6% 5% 8% 11% 31%	2840
	11th to 20th	Night	6% 5% 2 6% 6% 7% 6% 6% 9% 12% 36%	2840
	21st to end	Night	9% 10% 4 10% 6% 6% 7% 5% 8% 10% 24%	3087
August	1st to 10th	Night	6% 4 2 6% 5% 4 5% 4 8% 12% 43%	2855
	11th to 20th	Night	7% 5% 2 6% 5% 4 4 4 6% 9% 49%	3100
	21st to end	Night	9% 4 1 5% 3 3 4 4 6% 8% 52%	3476
September	1st to 10th	Night	9% 5% 2 6% 6% 5% 3 4 7% 8% 43%	2033
	11th to 20th	Night	13% 6% 2 6% 5% 4 4 3 5% 7% 44%	2090
	21st to end	Night	12% 4 2 5% 4 4 4 3 5% 6% 51%	2090
October	1st to 10th	Night	10% 6% 2 4 3 3 3 2 4 6% 59%	2090
	11th to 20th	Night	10% 6% 2 5% 3 3 3 3 4 5% 58%	2156
	21st to end	Night	12% 5% 1 4 3 3 3 3 4 4 57%	2532
November	1st to 10th	Night	12% 6% 1 4 3 3 4 3 4 5% 55%	2452
	11th to 20th	Night	12% 6% 2 5% 3 3 3 3 4 6% 53%	2470
	21st to end	Night	14% 6% 2 5% 4 4 4 3 5% 6% 46%	2470
December	1st to 10th	Night	17% 7% 3 6% 4 4 4 4 6% 6% 39%	2470
	11th to 20th	Night	16% 10% 2 5% 3 3 3 3 4 5% 47%	3042
	21st to end	Night	18% 10% 3 7% 5% 4 4 3 5% 7% 33%	4532

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	47% 3 7% 16% 22% 5%	2837
	11th to 20th	Day	36% 4 7% 23% 24% 5%	2840
	21st to end	Day	50% 3 4 16% 21% 5%	3321
February	1st to 10th	Day	47% 2 7% 19% 21% 4	1900
	11th to 20th	Day	46% 3 6% 19% 20% 6%	1858
	21st to end	Day	48% 3 7% 14% 20% 8%	1570
March	1st to 10th	Day	53% 4 9% 12% 14% 9%	3169
	11th to 20th	Day	39% 3 8% 18% 23% 9%	3480
	21st to end	Day	44% 5% 9% 19% 18% 4	3815
April	1st to 10th	Day	40% 4 9% 20% 20% 7%	2199
	11th to 20th	Day	38% 4 6% 19% 24% 8%	2254
	21st to end	Day	33% 5% 10% 27% 23% 3	2392
May	1st to 10th	Day	37% 6% 13% 23% 19% 2	4120
	11th to 20th	Day	45% 7% 12% 23% 12% 1	4085
	21st to end	Day	35% 6% 13% 26% 19% 2	4489
June	1st to 10th	Day	45% 6% 14% 22% 11% 2	2470
	11th to 20th	Day	32% 8% 19% 25% 15% 2	2470
	21st to end	Day	38% 8% 16% 23% 12% 2	2470
July	1st to 10th	Day	45% 12% 20% 18% 5% 1	4055
	11th to 20th	Day	42% 13% 18% 21% 6% 1	4051
	21st to end	Day	57% 11% 14% 13% 5%	4324
August	1st to 10th	Day	33% 8% 14% 33% 12%	4043
	11th to 20th	Day	33% 6% 17% 27% 14% 3	3765
	21st to end	Day	33% 7% 13% 23% 21% 3	4179
September	1st to 10th	Day	39% 7% 15% 17% 17% 5%	2128
	11th to 20th	Day	42% 6% 10% 20% 20% 2	2090
	21st to end	Day	38% 4 10% 19% 23% 6%	2090
October	1st to 10th	Day	26% 2 6% 13% 38% 14%	3480
	11th to 20th	Day	21% 3 4 16% 29% 27%	3339
	21st to end	Day	26% 3 5% 22% 32% 12%	3376
November	1st to 10th	Day	33% 2 7% 17% 31% 10%	1699
	11th to 20th	Day	34% 4 6% 18% 28% 10%	1710
	21st to end	Day	38% 4 7% 19% 25% 7%	1710
December	1st to 10th	Day	47% 3 6% 20% 18% 6%	1710
	11th to 20th	Day	45% 3 6% 16% 23% 7%	2150
	21st to end	Day	47% 5% 7% 18% 20% 3	3124
January	1st to 10th	Night	45% 4 6% 17% 25% 4	4109
	11th to 20th	Night	41% 4 5% 22% 21% 7%	4120
	21st to end	Night	51% 3 3 12% 26% 5%	4331
February	1st to 10th	Night	44% 3 7% 19% 19% 8%	2280
	11th to 20th	Night	46% 3 5% 17% 20% 8%	2219
	21st to end	Night	46% 4 7% 16% 18% 9%	1884
March	1st to 10th	Night	52% 4 9% 14% 14% 7%	3683
	11th to 20th	Night	33% 5% 9% 17% 26% 11%	3480
	21st to end	Night	43% 4 6% 20% 22% 5%	3817
April	1st to 10th	Night	36% 4 10% 20% 23% 7%	1995
	11th to 20th	Night	35% 4 7% 21% 24% 10%	1875
	21st to end	Night	31% 4 9% 30% 21% 5%	1786
May	1st to 10th	Night	36% 8% 14% 23% 17% 2	2840
	11th to 20th	Night	41% 6% 14% 26% 11% 1	2813
	21st to end	Night	27% 7% 16% 29% 19% 2	3087
June	1st to 10th	Night	36% 8% 19% 22% 14% 1	1710
	11th to 20th	Night	27% 7% 23% 26% 15% 2	1710
	21st to end	Night	30% 7% 22% 21% 15% 4	1710
July	1st to 10th	Night	45% 10% 19% 19% 6% 1	2795
	11th to 20th	Night	36% 12% 21% 22% 7% 1	2786
	21st to end	Night	52% 12% 15% 15% 5% 1	2988
August	1st to 10th	Night	31% 7% 16% 35% 10% 1	2844
	11th to 20th	Night	32% 6% 15% 30% 16% 1	3130
	21st to end	Night	29% 7% 14% 19% 28% 3	3476
September	1st to 10th	Night	36% 7% 15% 19% 16% 6%	2033
	11th to 20th	Night	39% 6% 11% 22% 19% 3	2090
	21st to end	Night	34% 4 12% 21% 22% 8%	2090
October	1st to 10th	Night	24% 3 7% 15% 38% 14%	3480
	11th to 20th	Night	18% 2 4 17% 32% 26%	3577
	21st to end	Night	23% 3 3 23% 31% 17%	4168
November	1st to 10th	Night	32% 3 8% 18% 27% 12%	2452
	11th to 20th	Night	33% 3 5% 20% 28% 11%	2470
	21st to end	Night	39% 3 6% 19% 26% 7%	2470
December	1st to 10th	Night	44% 5% 8% 20% 19% 5%	2470
	11th to 20th	Night	40% 3 6% 16% 28% 6%	3044
	21st to end	Night	49% 5% 6% 21% 18% 2	4532

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% 27% 34% 10% 3	270
	11th to 20th	Day	30% 21% 33% 10% 5% 1	270
	21st to end	Day	25% 26% 36% 9% 3 1	297
February	1st to 10th	Day	27% 23% 34% 13% 3	270
	11th to 20th	Day	34% 20% 34% 11% 1	270
	21st to end	Day	29% 25% 36% 9% 1	225
March	1st to 10th	Day	29% 18% 33% 15% 4 1	293
	11th to 20th	Day	25% 18% 32% 17% 6% 1	460
	21st to end	Day	22% 18% 37% 18% 5% 1	506
April	1st to 10th	Day	19% 19% 32% 19% 10% 2	460
	11th to 20th	Day	13% 18% 34% 22% 10% 2	452
	21st to end	Day	16% 10% 33% 24% 14% 2	460
May	1st to 10th	Day	13% 11% 32% 26% 13% 4	463
	11th to 20th	Day	14% 4 25% 30% 18% 9%	487
	21st to end	Day	14% 5% 20% 31% 18% 12%	529
June	1st to 10th	Day	13% 2 20% 28% 25% 12%	490
	11th to 20th	Day	6% 3 17% 27% 27% 20%	490
	21st to end	Day	11% 2 16% 31% 25% 15%	490
July	1st to 10th	Day	10% 3 7% 28% 29% 23%	485
	11th to 20th	Day	8% 1 7% 23% 32% 29%	484
	21st to end	Day	8% 2 7% 25% 36% 21%	532
August	1st to 10th	Day	12% 2 11% 26% 28% 21%	486
	11th to 20th	Day	13% 2 8% 31% 28% 18%	479
	21st to end	Day	17% 1 8% 27% 28% 19%	539
September	1st to 10th	Day	16% 2 11% 26% 29% 17%	490
	11th to 20th	Day	20% 2 12% 27% 26% 12%	490
	21st to end	Day	16% 3 18% 25% 28% 10%	490
October	1st to 10th	Day	14% 3 23% 33% 18% 8%	490
	11th to 20th	Day	15% 10% 24% 27% 19% 4	490
	21st to end	Day	18% 10% 24% 26% 18% 3	511
November	1st to 10th	Day	20% 10% 28% 26% 13% 3	279
	11th to 20th	Day	17% 19% 37% 20% 7% 1	270
	21st to end	Day	12% 18% 42% 20% 8% 1	270
December	1st to 10th	Day	27% 22% 30% 17% 4	270
	11th to 20th	Day	26% 18% 31% 20% 4 1	270
	21st to end	Day	29% 16% 34% 16% 4 1	297
January	1st to 10th	Night	25% 21% 29% 20% 5%	760
	11th to 20th	Night	22% 18% 29% 24% 7%	760
	21st to end	Night	21% 20% 34% 22% 4	836
February	1st to 10th	Night	21% 14% 34% 26% 5%	760
	11th to 20th	Night	26% 20% 31% 22% 1	743
	21st to end	Night	26% 19% 35% 17% 3	628
March	1st to 10th	Night	18% 18% 33% 25% 5%	760
	11th to 20th	Night	18% 15% 34% 22% 10% 1	760
	21st to end	Night	18% 17% 31% 26% 8%	836
April	1st to 10th	Night	15% 15% 33% 24% 12% 1	665
	11th to 20th	Night	19% 13% 29% 26% 12% 1	563
	21st to end	Night	11% 10% 25% 36% 15% 2	570
May	1st to 10th	Night	12% 8% 25% 33% 20% 2	570
	11th to 20th	Night	13% 4 23% 30% 26% 4	561
	21st to end	Night	12% 1 14% 33% 33% 7%	617
June	1st to 10th	Night	9% 1 15% 36% 32% 8%	570
	11th to 20th	Night	4 2 15% 29% 35% 15%	570
	21st to end	Night	8% 10% 34% 41% 6%	570
July	1st to 10th	Night	10% 2 8% 25% 41% 15%	555
	11th to 20th	Night	9% 5% 24% 45% 16%	552
	21st to end	Night	8% 1 6% 29% 45% 11%	624
August	1st to 10th	Night	10% 4 32% 41% 13%	567
	11th to 20th	Night	9% 2 7% 32% 40% 10%	564
	21st to end	Night	17% 1 6% 27% 39% 11%	627
September	1st to 10th	Night	11% 1 10% 26% 39% 13%	703
	11th to 20th	Night	17% 2 10% 29% 36% 5%	760
	21st to end	Night	16% 2 14% 33% 32% 3	760
October	1st to 10th	Night	13% 3 22% 31% 24% 6%	760
	11th to 20th	Night	12% 9% 25% 30% 22% 3	760
	21st to end	Night	15% 9% 22% 33% 18% 3	836
November	1st to 10th	Night	15% 7% 25% 30% 22% 2	755
	11th to 20th	Night	16% 13% 28% 29% 12% 1	760
	21st to end	Night	18% 13% 29% 28% 11% 1	760
December	1st to 10th	Night	22% 16% 29% 23% 9% 1	760
	11th to 20th	Night	23% 14% 28% 26% 8% 1	760
	21st to end	Night	27% 14% 28% 25% 6%	836

Page generated at 2024-11-01 22:47:32. Version ac07

Copyright © 2024 Attilla Danko.