Discovery Park of America
Clear Sky Chart
History

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

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% 4 4 4 4 6% 7% 44%	100992
	Night	13% 6% 2 6% 4 4 4 3 5% 7% 47%	98208
Transparency	Day	38% 6% 10% 24% 19% 4	104680
	Night	35% 5% 10% 24% 21% 5%	102663
Seeing	Day	15% 7% 21% 25% 21% 10%	15430
	Night	16% 6% 24% 33% 18% 3	25208

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	14% 11% 3 9% 5% 4 3 3 4 4 41%	2527
	11th to 20th	Day	18% 9% 2 6% 4 4 3 2 3 5% 44%	2731
	21st to end	Day	23% 11% 3 7% 4 3 3 3 4 5% 35%	3135
February	1st to 10th	Day	19% 10% 3 6% 4 3 4 3 4 5% 39%	1869
	11th to 20th	Day	19% 10% 3 6% 5% 4 3 2 4 6% 38%	1848
	21st to end	Day	20% 10% 3 7% 5% 4 4 3 5% 6% 34%	1570
March	1st to 10th	Day	19% 13% 3 7% 4 3 3 3 5% 5% 35%	3120
	11th to 20th	Day	14% 7% 2 6% 4 3 3 3 5% 5% 48%	3370
	21st to end	Day	12% 7% 3 7% 5% 4 5% 4 5% 7% 42%	4128
April	1st to 10th	Day	13% 6% 2 7% 4 4 3 4 5% 7% 46%	2280
	11th to 20th	Day	16% 7% 2 7% 5% 4 4 3 5% 6% 42%	2254
	21st to end	Day	16% 7% 3 6% 4 3 4 3 5% 7% 41%	2280
May	1st to 10th	Day	14% 7% 2 7% 6% 5% 5% 4 7% 9% 34%	3888
	11th to 20th	Day	15% 7% 2 6% 4 5% 5% 4 6% 8% 37%	4081
	21st to end	Day	10% 7% 2 7% 5% 5% 6% 4 6% 9% 39%	4688
June	1st to 10th	Day	8% 5% 2 5% 5% 5% 4 4 7% 10% 45%	2660
	11th to 20th	Day	4 4 2 5% 4 4 6% 5% 7% 11% 48%	2660
	21st to end	Day	4 5% 1 5% 5% 5% 6% 5% 8% 11% 46%	2660
July	1st to 10th	Day	7% 5% 2 6% 5% 6% 6% 5% 8% 10% 41%	4440
	11th to 20th	Day	6% 4 2 5% 5% 4 5% 5% 8% 11% 46%	4440
	21st to end	Day	9% 9% 4 10% 6% 5% 6% 4 6% 8% 32%	4575
August	1st to 10th	Day	3 3 2 4 3 3 5% 4 7% 10% 58%	3785
	11th to 20th	Day	8% 5% 2 6% 3 4 5% 4 6% 10% 46%	3729
	21st to end	Day	5% 3 2 4 3 3 3 4 6% 8% 58%	4180
September	1st to 10th	Day	10% 5% 2 6% 4 4 4 4 6% 7% 47%	2280
	11th to 20th	Day	13% 5% 2 5% 4 3 4 3 5% 8% 47%	2181
	21st to end	Day	12% 5% 2 4 3 4 4 3 4 7% 52%	2090
October	1st to 10th	Day	8% 4 2 5% 3 3 3 3 5% 5% 59%	2035
	11th to 20th	Day	13% 5% 2 4 4 3 3 3 5% 5% 54%	1900
	21st to end	Day	18% 6% 2 4 3 3 3 3 4 5% 49%	2038
November	1st to 10th	Day	12% 6% 2 5% 3 3 3 3 4 5% 54%	1762
	11th to 20th	Day	14% 7% 2 5% 3 3 3 3 4 5% 51%	1710
	21st to end	Day	17% 7% 3 7% 3 4 4 3 4 6% 43%	1710
December	1st to 10th	Day	18% 8% 3 6% 5% 4 5% 3 4 6% 40%	1687
	11th to 20th	Day	15% 8% 3 7% 5% 4 3 3 5% 6% 41%	1918
	21st to end	Day	15% 12% 3 9% 5% 5% 5% 3 5% 5% 33%	2783
January	1st to 10th	Night	18% 7% 3 4 3 3 4 3 5% 6% 42%	4428
	11th to 20th	Night	16% 8% 3 7% 5% 4 4 3 4 5% 42%	4234
	21st to end	Night	24% 8% 2 5% 3 3 3 3 4 5% 40%	4532
February	1st to 10th	Night	21% 9% 3 6% 5% 3 3 3 4 5% 38%	2308
	11th to 20th	Night	18% 6% 3 7% 5% 4 4 3 4 5% 42%	2218
	21st to end	Night	19% 7% 3 6% 4 4 4 3 5% 6% 38%	1884
March	1st to 10th	Night	21% 10% 3 6% 4 3 4 3 4 5% 38%	3733
	11th to 20th	Night	13% 7% 3 5% 4 4 3 3 4 6% 49%	3618
	21st to end	Night	12% 7% 3 7% 5% 4 4 4 6% 6% 42%	3503
April	1st to 10th	Night	11% 5% 2 6% 4 3 3 3 6% 7% 49%	1900
	11th to 20th	Night	15% 6% 2 5% 4 4 4 2 4 6% 47%	1875
	21st to end	Night	14% 5% 2 7% 5% 4 4 4 6% 7% 43%	1900
May	1st to 10th	Night	17% 7% 2 6% 3 3 4 4 6% 7% 41%	3003
	11th to 20th	Night	12% 7% 3 6% 4 4 4 4 5% 7% 45%	2812
	21st to end	Night	8% 5% 2 6% 4 5% 6% 5% 7% 9% 42%	2871
June	1st to 10th	Night	8% 6% 3 6% 4 5% 4 4 7% 7% 46%	1520
	11th to 20th	Night	4 3 1 4 4 4 4 4 6% 10% 57%	1520
	21st to end	Night	2 2 2 3 4 4 5% 5% 8% 11% 54%	1520
July	1st to 10th	Night	6% 5% 2 6% 4 4 6% 5% 7% 11% 44%	2530
	11th to 20th	Night	4 4 1 5% 4 4 4 4 6% 11% 53%	2530
	21st to end	Night	7% 9% 4 9% 5% 5% 5% 4 6% 8% 37%	2970
August	1st to 10th	Night	2 2 1 4 3 3 4 4 6% 7% 63%	3140
	11th to 20th	Night	4 3 1 5% 3 4 5% 4 7% 9% 54%	3100
	21st to end	Night	4 3 1 4 3 3 3 3 5% 9% 62%	3476
September	1st to 10th	Night	8% 5% 2 4 4 4 3 3 4 7% 56%	1900
	11th to 20th	Night	8% 6% 2 5% 5% 4 4 3 5% 6% 53%	1978
	21st to end	Night	9% 4 2 5% 3 3 4 3 5% 6% 55%	2090
October	1st to 10th	Night	7% 4 1 4 2 4 3 3 4 6% 61%	2141
	11th to 20th	Night	13% 4 2 4 3 3 3 2 4 5% 57%	2280
	21st to end	Night	16% 7% 2 5% 3 3 3 3 4 6% 50%	2559
November	1st to 10th	Night	12% 5% 2 4 3 3 2 3 4 5% 55%	2536
	11th to 20th	Night	13% 5% 2 5% 3 3 3 3 5% 6% 53%	2477
	21st to end	Night	16% 6% 2 5% 4 4 3 3 4 6% 48%	2470
December	1st to 10th	Night	18% 9% 2 6% 5% 3 4 3 5% 5% 41%	2489
	11th to 20th	Night	17% 8% 3 5% 4 4 4 3 4 5% 45%	3279
	21st to end	Night	16% 8% 4 8% 5% 5% 5% 4 5% 6% 34%	4884

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% 25% 16% 2	2528
	11th to 20th	Day	44% 3 9% 26% 16% 2	2731
	21st to end	Day	52% 4 8% 21% 13% 2	3135
February	1st to 10th	Day	49% 4 9% 23% 14% 2	1869
	11th to 20th	Day	48% 5% 9% 21% 13% 4	1858
	21st to end	Day	52% 4 8% 17% 14% 5%	1570
March	1st to 10th	Day	52% 3 7% 16% 14% 7%	3120
	11th to 20th	Day	39% 4 9% 25% 19% 5%	3370
	21st to end	Day	41% 5% 12% 22% 19% 1	4128
April	1st to 10th	Day	38% 5% 10% 26% 19% 2	2280
	11th to 20th	Day	43% 4 9% 22% 18% 4	2254
	21st to end	Day	41% 6% 9% 25% 16% 1	2280
May	1st to 10th	Day	44% 8% 14% 20% 13% 1	3923
	11th to 20th	Day	43% 8% 11% 23% 14% 1	4085
	21st to end	Day	39% 9% 11% 22% 18% 1	4701
June	1st to 10th	Day	33% 8% 14% 23% 20% 2	2660
	11th to 20th	Day	28% 8% 12% 28% 21% 4	2660
	21st to end	Day	29% 10% 14% 24% 18% 5%	2660
July	1st to 10th	Day	35% 8% 15% 26% 13% 3	4371
	11th to 20th	Day	29% 7% 12% 35% 13% 3	4365
	21st to end	Day	50% 6% 12% 22% 9% 1	4431
August	1st to 10th	Day	20% 7% 16% 30% 24% 2	3773
	11th to 20th	Day	34% 6% 15% 25% 17% 3	3765
	21st to end	Day	24% 5% 11% 34% 24% 3	4179
September	1st to 10th	Day	34% 7% 10% 24% 20% 4	2280
	11th to 20th	Day	36% 7% 8% 22% 24% 4	2181
	21st to end	Day	34% 4 8% 24% 25% 6%	2090
October	1st to 10th	Day	17% 3 6% 16% 43% 15%	3386
	11th to 20th	Day	23% 2 6% 21% 31% 16%	3140
	21st to end	Day	29% 3 4 27% 31% 6%	3340
November	1st to 10th	Day	33% 4 8% 24% 25% 6%	1762
	11th to 20th	Day	37% 3 7% 23% 24% 6%	1710
	21st to end	Day	44% 4 7% 23% 19% 4	1710
December	1st to 10th	Day	46% 5% 8% 23% 15% 2	1687
	11th to 20th	Day	45% 4 9% 23% 18% 2	1915
	21st to end	Day	51% 5% 11% 20% 12% 2	2783
January	1st to 10th	Night	42% 4 7% 30% 15% 1	4428
	11th to 20th	Night	45% 4 8% 24% 16% 3	4234
	21st to end	Night	46% 4 9% 24% 15% 2	4532
February	1st to 10th	Night	50% 4 9% 18% 17% 2	2308
	11th to 20th	Night	45% 4 8% 21% 18% 4	2219
	21st to end	Night	47% 4 8% 18% 17% 5%	1884
March	1st to 10th	Night	49% 5% 8% 14% 17% 8%	3733
	11th to 20th	Night	37% 5% 9% 22% 17% 9%	3618
	21st to end	Night	41% 5% 10% 26% 17% 1	3503
April	1st to 10th	Night	33% 4 12% 25% 21% 5%	1900
	11th to 20th	Night	38% 5% 7% 21% 21% 8%	1875
	21st to end	Night	38% 7% 9% 24% 18% 3	1900
May	1st to 10th	Night	42% 8% 14% 23% 11% 2	3033
	11th to 20th	Night	37% 10% 13% 22% 16% 1	2813
	21st to end	Night	34% 8% 13% 28% 15% 2	2879
June	1st to 10th	Night	34% 7% 11% 22% 23% 2	1520
	11th to 20th	Night	22% 6% 14% 30% 23% 5%	1520
	21st to end	Night	22% 9% 17% 25% 20% 7%	1520
July	1st to 10th	Night	32% 8% 16% 27% 15% 3	2490
	11th to 20th	Night	25% 7% 12% 36% 17% 4	2482
	21st to end	Night	43% 7% 15% 21% 13%	2876
August	1st to 10th	Night	17% 7% 13% 38% 23% 1	3129
	11th to 20th	Night	25% 7% 15% 31% 20% 3	3130
	21st to end	Night	20% 5% 11% 35% 26% 3	3476
September	1st to 10th	Night	28% 5% 10% 28% 22% 6%	1900
	11th to 20th	Night	32% 6% 8% 24% 25% 4	1978
	21st to end	Night	29% 4 12% 23% 25% 7%	2090
October	1st to 10th	Night	16% 3 5% 16% 41% 18%	3570
	11th to 20th	Night	20% 2 4 17% 40% 16%	3779
	21st to end	Night	27% 3 6% 25% 29% 11%	4207
November	1st to 10th	Night	32% 4 6% 26% 27% 6%	2536
	11th to 20th	Night	33% 3 7% 22% 25% 9%	2477
	21st to end	Night	39% 4 7% 24% 23% 3	2470
December	1st to 10th	Night	45% 4 9% 22% 17% 3	2489
	11th to 20th	Night	41% 4 8% 22% 21% 3	3281
	21st to end	Night	49% 5% 11% 19% 13% 3	4884

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	27% 13% 36% 19% 4 1	270
	11th to 20th	Day	26% 17% 38% 15% 3 1	270
	21st to end	Day	22% 15% 41% 18% 4	297
February	1st to 10th	Day	28% 12% 36% 17% 6% 1	270
	11th to 20th	Day	31% 16% 36% 14% 3	270
	21st to end	Day	35% 15% 30% 18% 2	225
March	1st to 10th	Day	25% 12% 36% 20% 6% 1	270
	11th to 20th	Day	21% 17% 39% 20% 2	270
	21st to end	Day	24% 12% 34% 21% 8% 1	482
April	1st to 10th	Day	19% 13% 31% 26% 10% 1	460
	11th to 20th	Day	20% 14% 28% 26% 10% 2	452
	21st to end	Day	20% 8% 34% 23% 11% 4	460
May	1st to 10th	Day	17% 11% 26% 30% 11% 5%	463
	11th to 20th	Day	18% 5% 21% 26% 19% 10%	487
	21st to end	Day	10% 4 21% 30% 23% 12%	650
June	1st to 10th	Day	12% 3 16% 24% 28% 17%	680
	11th to 20th	Day	6% 2 13% 32% 34% 14%	680
	21st to end	Day	5% 2 18% 35% 26% 14%	680
July	1st to 10th	Day	7% 3 10% 27% 29% 25%	671
	11th to 20th	Day	8% 1 9% 27% 36% 19%	668
	21st to end	Day	8% 3 9% 28% 32% 19%	739
August	1st to 10th	Day	7% 2 8% 27% 38% 17%	486
	11th to 20th	Day	13% 3 10% 27% 33% 14%	479
	21st to end	Day	11% 1 6% 20% 37% 25%	539
September	1st to 10th	Day	11% 3 8% 26% 32% 20%	490
	11th to 20th	Day	13% 1 8% 20% 36% 21%	490
	21st to end	Day	17% 4 14% 28% 24% 12%	490
October	1st to 10th	Day	9% 2 19% 31% 32% 7%	435
	11th to 20th	Day	14% 9% 32% 24% 14% 7%	300
	21st to end	Day	23% 10% 27% 23% 15% 2	330
November	1st to 10th	Day	16% 7% 28% 32% 13% 4	300
	11th to 20th	Day	10% 13% 36% 28% 13% 1	270
	21st to end	Day	22% 10% 29% 25% 13% 2	270
December	1st to 10th	Day	22% 14% 33% 19% 10% 1	270
	11th to 20th	Day	23% 11% 31% 23% 11% 1	270
	21st to end	Day	25% 18% 33% 20% 4 1	297
January	1st to 10th	Night	24% 10% 34% 27% 5%	950
	11th to 20th	Night	25% 11% 35% 24% 4	950
	21st to end	Night	22% 9% 39% 27% 2	1045
February	1st to 10th	Night	25% 9% 35% 26% 4	788
	11th to 20th	Night	22% 13% 39% 24% 2	743
	21st to end	Night	25% 14% 38% 22% 2	628
March	1st to 10th	Night	22% 11% 32% 31% 5%	760
	11th to 20th	Night	22% 11% 35% 26% 6%	656
	21st to end	Night	18% 9% 33% 30% 9%	627
April	1st to 10th	Night	14% 10% 38% 29% 9%	570
	11th to 20th	Night	17% 10% 28% 32% 11% 2	563
	21st to end	Night	14% 6% 33% 34% 12% 1	570
May	1st to 10th	Night	16% 5% 28% 36% 13% 1	570
	11th to 20th	Night	13% 3 20% 40% 21% 2	561
	21st to end	Night	8% 3 16% 41% 27% 4	617
June	1st to 10th	Night	11% 2 11% 42% 30% 5%	570
	11th to 20th	Night	5% 10% 46% 36% 3	570
	21st to end	Night	4 1 9% 44% 37% 5%	570
July	1st to 10th	Night	6% 2 5% 32% 45% 9%	555
	11th to 20th	Night	7% 1 8% 30% 46% 9%	552
	21st to end	Night	6% 2 8% 33% 42% 9%	624
August	1st to 10th	Night	5% 1 5% 37% 46% 8%	567
	11th to 20th	Night	6% 2 4 43% 40% 5%	564
	21st to end	Night	8% 1 4 28% 47% 11%	627
September	1st to 10th	Night	10% 2 6% 33% 43% 6%	570
	11th to 20th	Night	10% 2 8% 34% 38% 7%	648
	21st to end	Night	11% 4 15% 36% 29% 5%	760
October	1st to 10th	Night	9% 3 15% 38% 31% 4	760
	11th to 20th	Night	15% 4 26% 35% 19% 1	760
	21st to end	Night	20% 5% 27% 34% 12% 1	836
November	1st to 10th	Night	15% 5% 27% 39% 13% 1	780
	11th to 20th	Night	14% 7% 34% 33% 11%	763
	21st to end	Night	20% 8% 28% 32% 10% 1	760
December	1st to 10th	Night	23% 8% 31% 31% 8%	779
	11th to 20th	Night	22% 7% 29% 33% 7%	950
	21st to end	Night	25% 11% 32% 27% 4	1045

Page generated at 2024-11-08 05:44:50. Version ac07

Copyright © 2024 Attilla Danko.