Auburn-Opelika Airport
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Auburn-Opelika Airport 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% 6% 2 6% 5% 5% 5% 4 6% 8% 42%	100867
	Night	12% 6% 2 6% 4 4 4 4 6% 8% 44%	98111
Transparency	Day	37% 8% 11% 19% 18% 7%	104724
	Night	36% 7% 11% 18% 20% 8%	102380
Seeing	Day	14% 9% 22% 25% 20% 10%	14762
	Night	14% 7% 23% 30% 21% 4	24733

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% 9% 3 6% 3 3 3 4 5% 6% 40%	2836
	11th to 20th	Day	12% 5% 2 4 3 3 4 3 5% 7% 53%	2851
	21st to end	Day	23% 10% 3 5% 3 2 3 2 4 5% 40%	3476
February	1st to 10th	Day	17% 8% 3 6% 5% 4 4 3 5% 6% 38%	1900
	11th to 20th	Day	20% 7% 2 6% 3 3 4 3 4 5% 42%	1848
	21st to end	Day	16% 8% 3 7% 4 4 4 3 4 7% 39%	1570
March	1st to 10th	Day	23% 8% 3 7% 4 3 4 4 5% 5% 35%	3120
	11th to 20th	Day	12% 6% 2 6% 4 4 4 4 5% 7% 44%	3475
	21st to end	Day	17% 6% 2 6% 5% 4 5% 4 5% 7% 41%	3815
April	1st to 10th	Day	13% 5% 2 6% 4 4 5% 4 5% 7% 45%	2242
	11th to 20th	Day	12% 5% 2 6% 4 4 4 3 5% 7% 46%	2254
	21st to end	Day	8% 4 2 5% 4 4 4 4 5% 8% 53%	2314
May	1st to 10th	Day	9% 5% 3 6% 5% 4 4 4 6% 9% 44%	4082
	11th to 20th	Day	16% 6% 2 6% 4 5% 5% 4 6% 8% 38%	4081
	21st to end	Day	7% 5% 2 6% 4 5% 5% 5% 7% 9% 46%	4476
June	1st to 10th	Day	9% 7% 2 8% 6% 6% 6% 6% 9% 9% 32%	2470
	11th to 20th	Day	6% 3 1 5% 6% 6% 6% 6% 9% 11% 41%	2470
	21st to end	Day	6% 5% 2 8% 6% 7% 7% 5% 9% 10% 34%	2470
July	1st to 10th	Day	10% 6% 2 8% 6% 7% 7% 8% 9% 12% 25%	4120
	11th to 20th	Day	7% 5% 2 8% 7% 7% 7% 6% 8% 10% 32%	4120
	21st to end	Day	10% 7% 2 8% 7% 8% 8% 7% 10% 12% 22%	4466
August	1st to 10th	Day	5% 3 1 5% 5% 6% 6% 5% 9% 14% 42%	3849
	11th to 20th	Day	8% 5% 2 6% 4 5% 5% 4 6% 9% 48%	3729
	21st to end	Day	7% 5% 2 4 4 5% 5% 5% 8% 10% 46%	4180
September	1st to 10th	Day	10% 6% 3 8% 5% 7% 7% 5% 6% 8% 36%	2148
	11th to 20th	Day	14% 6% 2 7% 4 5% 6% 4 6% 7% 40%	2090
	21st to end	Day	11% 5% 2 6% 5% 4 5% 4 5% 6% 49%	2090
October	1st to 10th	Day	10% 6% 2 5% 4 3 3 4 4 6% 54%	2090
	11th to 20th	Day	10% 4 2 4 3 3 3 4 5% 7% 57%	2081
	21st to end	Day	12% 5% 2 4 3 3 3 3 4 5% 56%	2048
November	1st to 10th	Day	10% 6% 2 4 4 4 4 3 4 5% 55%	1699
	11th to 20th	Day	13% 5% 2 4 3 2 4 2 4 5% 56%	1710
	21st to end	Day	14% 6% 2 5% 4 4 5% 3 5% 6% 46%	1710
December	1st to 10th	Day	17% 6% 2 5% 4 4 5% 4 4 7% 42%	1710
	11th to 20th	Day	17% 7% 3 6% 4 4 3 3 4 5% 42%	2153
	21st to end	Day	21% 7% 3 6% 4 4 4 3 5% 6% 38%	3124
January	1st to 10th	Night	17% 11% 2 5% 3 4 4 3 5% 5% 40%	4109
	11th to 20th	Night	12% 7% 2 5% 4 4 4 3 5% 6% 47%	4106
	21st to end	Night	23% 12% 2 5% 3 3 3 2 3 4 40%	4180
February	1st to 10th	Night	15% 8% 3 7% 5% 3 3 3 4 6% 43%	2280
	11th to 20th	Night	20% 7% 2 6% 4 3 3 3 4 5% 44%	2218
	21st to end	Night	16% 7% 3 6% 5% 4 4 3 5% 7% 41%	1884
March	1st to 10th	Night	22% 10% 3 6% 3 3 3 3 4 5% 36%	3733
	11th to 20th	Night	12% 6% 1 5% 4 5% 5% 3 6% 7% 46%	3485
	21st to end	Night	13% 6% 2 6% 4 4 4 4 6% 7% 44%	3817
April	1st to 10th	Night	11% 5% 2 5% 5% 3 4 4 6% 7% 46%	1952
	11th to 20th	Night	13% 5% 2 5% 3 3 3 3 6% 9% 48%	1875
	21st to end	Night	7% 5% 2 5% 3 4 4 3 4 7% 55%	1862
May	1st to 10th	Night	7% 5% 3 6% 5% 4 5% 4 7% 9% 46%	2813
	11th to 20th	Night	16% 8% 2 6% 4 4 4 3 5% 6% 41%	2812
	21st to end	Night	6% 4 2 4 4 4 5% 5% 7% 12% 49%	3079
June	1st to 10th	Night	7% 6% 2 8% 6% 6% 6% 5% 8% 11% 33%	1710
	11th to 20th	Night	4 4 2 5% 4 5% 6% 5% 8% 11% 46%	1710
	21st to end	Night	5% 6% 2 6% 6% 5% 5% 6% 7% 13% 39%	1710
July	1st to 10th	Night	10% 6% 3 8% 7% 7% 7% 6% 9% 12% 25%	2840
	11th to 20th	Night	7% 4 2 7% 4 6% 6% 6% 10% 12% 35%	2840
	21st to end	Night	10% 8% 4 8% 6% 6% 7% 6% 8% 12% 25%	3087
August	1st to 10th	Night	5% 4 2 7% 4 5% 6% 6% 8% 13% 40%	3074
	11th to 20th	Night	7% 4 2 5% 4 4 5% 4 7% 11% 48%	3100
	21st to end	Night	7% 5% 2 5% 3 4 4 4 6% 10% 52%	3476
September	1st to 10th	Night	9% 6% 2 6% 5% 4 5% 6% 7% 9% 42%	2011
	11th to 20th	Night	13% 7% 3 6% 4 4 5% 4 6% 7% 43%	2090
	21st to end	Night	9% 5% 2 6% 4 4 4 3 5% 7% 50%	2090
October	1st to 10th	Night	8% 4 2 5% 3 3 3 3 5% 6% 57%	2090
	11th to 20th	Night	9% 4 1 5% 3 2 3 3 4 6% 59%	2096
	21st to end	Night	11% 5% 2 4 3 3 3 2 3 4 59%	2546
November	1st to 10th	Night	9% 4 1 5% 3 3 4 4 4 5% 57%	2452
	11th to 20th	Night	12% 5% 2 4 3 3 3 3 4 5% 56%	2470
	21st to end	Night	13% 6% 2 6% 4 3 3 3 4 6% 49%	2470
December	1st to 10th	Night	17% 5% 2 6% 4 4 3 3 4 6% 44%	2470
	11th to 20th	Night	17% 6% 2 6% 4 3 3 2 4 6% 46%	3042
	21st to end	Night	19% 7% 2 8% 4 4 4 3 5% 7% 36%	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	44% 4 5% 18% 23% 7%	2837
	11th to 20th	Day	31% 4 5% 22% 28% 10%	2851
	21st to end	Day	47% 4 5% 13% 20% 10%	3476
February	1st to 10th	Day	47% 4 7% 16% 19% 7%	1900
	11th to 20th	Day	44% 5% 5% 15% 22% 9%	1858
	21st to end	Day	44% 5% 7% 15% 18% 10%	1570
March	1st to 10th	Day	49% 7% 9% 13% 16% 6%	3120
	11th to 20th	Day	37% 7% 8% 16% 21% 12%	3475
	21st to end	Day	41% 6% 11% 16% 17% 9%	3815
April	1st to 10th	Day	37% 7% 10% 21% 17% 10%	2242
	11th to 20th	Day	36% 5% 9% 19% 23% 9%	2254
	21st to end	Day	29% 7% 10% 22% 27% 5%	2314
May	1st to 10th	Day	32% 9% 13% 23% 20% 3	4120
	11th to 20th	Day	40% 9% 12% 25% 12% 2	4085
	21st to end	Day	30% 9% 14% 27% 18% 2	4489
June	1st to 10th	Day	41% 12% 15% 19% 11% 2	2470
	11th to 20th	Day	32% 11% 17% 24% 14% 2	2470
	21st to end	Day	39% 13% 17% 19% 10% 3	2470
July	1st to 10th	Day	45% 14% 24% 13% 4 1	4055
	11th to 20th	Day	42% 12% 20% 21% 5%	4051
	21st to end	Day	50% 15% 20% 12% 4	4324
August	1st to 10th	Day	29% 11% 16% 30% 14% 1	3836
	11th to 20th	Day	31% 9% 15% 28% 16% 1	3765
	21st to end	Day	29% 10% 18% 26% 15% 3	4179
September	1st to 10th	Day	42% 10% 12% 16% 15% 5%	2148
	11th to 20th	Day	41% 9% 10% 17% 18% 4	2090
	21st to end	Day	35% 7% 9% 21% 21% 7%	2090
October	1st to 10th	Day	27% 4 7% 13% 27% 22%	3480
	11th to 20th	Day	16% 3 4 16% 26% 34%	3437
	21st to end	Day	20% 3 5% 18% 42% 13%	3350
November	1st to 10th	Day	33% 4 7% 15% 28% 14%	1699
	11th to 20th	Day	31% 3 7% 17% 26% 15%	1710
	21st to end	Day	37% 5% 8% 16% 24% 9%	1710
December	1st to 10th	Day	41% 6% 10% 16% 20% 7%	1710
	11th to 20th	Day	45% 4 5% 15% 24% 8%	2150
	21st to end	Day	46% 5% 7% 19% 20% 4	3124
January	1st to 10th	Night	44% 4 6% 14% 24% 8%	4109
	11th to 20th	Night	36% 4 6% 22% 23% 10%	4106
	21st to end	Night	49% 3 4 12% 24% 8%	4180
February	1st to 10th	Night	42% 4 7% 18% 18% 11%	2280
	11th to 20th	Night	42% 5% 5% 14% 22% 12%	2219
	21st to end	Night	41% 6% 8% 16% 15% 13%	1884
March	1st to 10th	Night	50% 6% 8% 15% 14% 8%	3733
	11th to 20th	Night	35% 7% 10% 15% 23% 11%	3485
	21st to end	Night	37% 6% 9% 18% 21% 9%	3817
April	1st to 10th	Night	35% 7% 10% 17% 20% 11%	1952
	11th to 20th	Night	32% 5% 7% 22% 23% 10%	1875
	21st to end	Night	28% 6% 11% 23% 24% 9%	1862
May	1st to 10th	Night	29% 11% 14% 23% 19% 4	2840
	11th to 20th	Night	42% 7% 12% 24% 13% 3	2813
	21st to end	Night	24% 9% 16% 28% 20% 3	3087
June	1st to 10th	Night	41% 11% 17% 15% 14% 1	1710
	11th to 20th	Night	28% 10% 20% 25% 15% 3	1710
	21st to end	Night	33% 11% 20% 19% 12% 4	1710
July	1st to 10th	Night	46% 14% 23% 11% 5% 1	2795
	11th to 20th	Night	36% 14% 23% 20% 6% 1	2786
	21st to end	Night	49% 12% 19% 15% 4	2988
August	1st to 10th	Night	34% 9% 17% 28% 11% 1	3063
	11th to 20th	Night	29% 8% 18% 28% 15% 2	3130
	21st to end	Night	28% 7% 18% 26% 19% 2	3476
September	1st to 10th	Night	36% 11% 16% 17% 15% 6%	2011
	11th to 20th	Night	38% 8% 13% 18% 16% 5%	2090
	21st to end	Night	34% 7% 9% 20% 21% 8%	2090
October	1st to 10th	Night	31% 4 8% 13% 25% 19%	3480
	11th to 20th	Night	16% 3 4 13% 30% 33%	3479
	21st to end	Night	21% 2 4 19% 35% 18%	4182
November	1st to 10th	Night	30% 5% 8% 16% 26% 16%	2452
	11th to 20th	Night	32% 3 5% 17% 27% 16%	2470
	21st to end	Night	38% 4 8% 16% 23% 11%	2470
December	1st to 10th	Night	40% 6% 9% 17% 22% 6%	2470
	11th to 20th	Night	40% 4 6% 15% 27% 8%	3044
	21st to end	Night	46% 6% 7% 19% 19% 3	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	22% 22% 35% 18% 3	270
	11th to 20th	Day	17% 23% 33% 19% 7% 1	270
	21st to end	Day	23% 24% 38% 12% 2 1	297
February	1st to 10th	Day	25% 20% 36% 13% 5%	270
	11th to 20th	Day	29% 21% 34% 13% 2	270
	21st to end	Day	22% 25% 42% 11%	225
March	1st to 10th	Day	21% 20% 34% 21% 3 1	270
	11th to 20th	Day	20% 16% 34% 22% 7% 1	455
	21st to end	Day	21% 16% 33% 22% 8% 1	506
April	1st to 10th	Day	18% 16% 28% 26% 10% 2	460
	11th to 20th	Day	14% 13% 34% 22% 13% 2	452
	21st to end	Day	12% 10% 26% 33% 17% 3	460
May	1st to 10th	Day	10% 10% 25% 29% 20% 6%	463
	11th to 20th	Day	11% 3 23% 29% 23% 10%	487
	21st to end	Day	11% 4 17% 32% 24% 13%	529
June	1st to 10th	Day	12% 3 14% 31% 28% 13%	490
	11th to 20th	Day	7% 2 16% 23% 29% 23%	490
	21st to end	Day	8% 3 14% 27% 27% 21%	490
July	1st to 10th	Day	8% 2 7% 22% 34% 26%	485
	11th to 20th	Day	6% 2 7% 18% 36% 31%	484
	21st to end	Day	7% 2 6% 22% 36% 27%	532
August	1st to 10th	Day	8% 1 8% 24% 34% 25%	486
	11th to 20th	Day	10% 2 6% 22% 38% 23%	479
	21st to end	Day	13% 2 9% 27% 31% 18%	539
September	1st to 10th	Day	10% 4 9% 29% 33% 15%	490
	11th to 20th	Day	15% 3 13% 30% 31% 9%	490
	21st to end	Day	9% 2 18% 29% 31% 10%	490
October	1st to 10th	Day	11% 7% 24% 32% 20% 6%	490
	11th to 20th	Day	10% 7% 24% 33% 20% 6%	490
	21st to end	Day	14% 9% 26% 29% 18% 4	497
November	1st to 10th	Day	19% 9% 26% 29% 15% 3	279
	11th to 20th	Day	15% 11% 41% 25% 7% 1	270
	21st to end	Day	14% 12% 36% 26% 11% 1	270
December	1st to 10th	Day	23% 16% 33% 21% 6% 1	270
	11th to 20th	Day	24% 21% 31% 21% 4	270
	21st to end	Day	25% 19% 27% 25% 4 1	297
January	1st to 10th	Night	22% 14% 34% 24% 5%	760
	11th to 20th	Night	19% 13% 30% 30% 8%	760
	21st to end	Night	23% 13% 37% 23% 3	836
February	1st to 10th	Night	19% 11% 32% 33% 6%	760
	11th to 20th	Night	23% 12% 35% 26% 5%	743
	21st to end	Night	18% 16% 38% 26% 3	628
March	1st to 10th	Night	16% 13% 35% 31% 6%	760
	11th to 20th	Night	15% 13% 35% 27% 10%	760
	21st to end	Night	14% 15% 31% 28% 11% 1	836
April	1st to 10th	Night	15% 10% 31% 29% 14%	622
	11th to 20th	Night	15% 8% 31% 29% 15% 2	563
	21st to end	Night	10% 8% 26% 35% 21% 1	570
May	1st to 10th	Night	7% 5% 25% 34% 25% 4	570
	11th to 20th	Night	10% 4 20% 35% 26% 5%	561
	21st to end	Night	8% 2 14% 34% 36% 6%	617
June	1st to 10th	Night	9% 2 12% 39% 34% 6%	570
	11th to 20th	Night	5% 3 11% 31% 37% 15%	570
	21st to end	Night	5% 2 7% 30% 45% 10%	570
July	1st to 10th	Night	7% 2 6% 25% 44% 17%	555
	11th to 20th	Night	5% 3 4 22% 47% 20%	552
	21st to end	Night	7% 1 5% 26% 47% 14%	624
August	1st to 10th	Night	5% 1 6% 26% 44% 18%	567
	11th to 20th	Night	10% 1 5% 26% 45% 12%	564
	21st to end	Night	13% 2 11% 26% 35% 13%	627
September	1st to 10th	Night	11% 2 10% 30% 38% 10%	681
	11th to 20th	Night	16% 2 13% 33% 31% 5%	760
	21st to end	Night	11% 1 17% 34% 33% 4	760
October	1st to 10th	Night	8% 4 24% 35% 24% 4	760
	11th to 20th	Night	11% 6% 24% 34% 22% 3	760
	21st to end	Night	13% 7% 23% 34% 21% 2	836
November	1st to 10th	Night	11% 6% 25% 35% 21% 2	755
	11th to 20th	Night	13% 11% 32% 30% 13% 1	760
	21st to end	Night	16% 9% 30% 32% 12% 1	760
December	1st to 10th	Night	19% 10% 29% 30% 11% 1	760
	11th to 20th	Night	21% 8% 33% 29% 8% 1	760
	21st to end	Night	25% 12% 27% 30% 6%	836

Page generated at 2024-11-01 21:47:40. Version ac07

Copyright © 2024 Attilla Danko.