Bladen Lake State Forest
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bladen Lake State Forest 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	13% 7% 3 7% 5% 5% 5% 4 6% 8% 39%	100982
	Night	13% 7% 2 6% 4 4 4 4 6% 7% 42%	98097
Transparency	Day	41% 6% 10% 19% 17% 6%	104629
	Night	39% 6% 11% 19% 18% 6%	102589
Seeing	Day	17% 10% 25% 26% 16% 6%	15623
	Night	16% 9% 25% 32% 16% 2	25792

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	15% 6% 2 5% 4 3 3 3 4 7% 48%	2836
	11th to 20th	Day	12% 6% 2 5% 4 4 4 3 4 6% 52%	2840
	21st to end	Day	15% 9% 3 6% 5% 4 4 3 4 5% 43%	3124
February	1st to 10th	Day	17% 8% 3 5% 4 4 4 3 4 6% 42%	1710
	11th to 20th	Day	19% 7% 2 5% 4 3 3 3 4 6% 45%	1720
	21st to end	Day	16% 8% 2 6% 5% 4 4 4 5% 6% 41%	1712
March	1st to 10th	Day	22% 9% 2 7% 4 4 3 4 4 5% 36%	3435
	11th to 20th	Day	10% 5% 2 5% 4 3 4 4 4 7% 54%	3480
	21st to end	Day	17% 7% 2 6% 4 3 4 2 4 5% 43%	3815
April	1st to 10th	Day	10% 5% 2 4 4 3 4 3 5% 8% 51%	2216
	11th to 20th	Day	10% 5% 2 5% 4 4 4 4 6% 7% 49%	2254
	21st to end	Day	11% 5% 2 6% 5% 4 3 4 5% 7% 48%	2280
May	1st to 10th	Day	8% 6% 3 8% 5% 6% 6% 5% 7% 10% 34%	3911
	11th to 20th	Day	17% 8% 3 7% 5% 5% 5% 4 6% 7% 34%	4081
	21st to end	Day	7% 4 2 6% 5% 6% 6% 5% 7% 9% 42%	4476
June	1st to 10th	Day	11% 7% 3 9% 6% 5% 7% 4 7% 8% 34%	2470
	11th to 20th	Day	10% 4 2 7% 6% 6% 6% 5% 7% 10% 36%	2470
	21st to end	Day	9% 6% 2 8% 6% 6% 7% 6% 10% 10% 30%	2470
July	1st to 10th	Day	8% 6% 3 9% 7% 7% 8% 6% 8% 11% 26%	4120
	11th to 20th	Day	10% 7% 3 11% 7% 7% 7% 5% 8% 10% 25%	4120
	21st to end	Day	10% 8% 3 10% 8% 7% 7% 6% 9% 10% 23%	4466
August	1st to 10th	Day	22% 11% 3 10% 6% 6% 6% 4 6% 8% 17%	4104
	11th to 20th	Day	10% 7% 3 9% 6% 5% 6% 5% 7% 10% 31%	3829
	21st to end	Day	7% 5% 3 7% 5% 5% 5% 5% 6% 9% 43%	4180
September	1st to 10th	Day	10% 5% 2 7% 5% 6% 5% 6% 7% 10% 37%	2280
	11th to 20th	Day	15% 8% 3 7% 4 5% 5% 5% 6% 7% 35%	2176
	21st to end	Day	17% 7% 3 8% 4 5% 4 4 6% 7% 36%	2033
October	1st to 10th	Day	15% 7% 2 6% 3 5% 4 3 4 6% 44%	1900
	11th to 20th	Day	10% 5% 2 5% 3 3 3 3 5% 7% 54%	1900
	21st to end	Day	11% 5% 2 5% 3 4 3 2 4 5% 57%	2090
November	1st to 10th	Day	12% 6% 2 4 3 3 3 3 4 6% 53%	1957
	11th to 20th	Day	14% 7% 2 5% 3 3 2 2 4 5% 51%	1900
	21st to end	Day	13% 5% 2 6% 4 3 3 3 4 6% 50%	1782
December	1st to 10th	Day	15% 8% 2 6% 6% 5% 5% 3 5% 6% 39%	1568
	11th to 20th	Day	15% 6% 2 4 3 3 3 2 4 5% 53%	2153
	21st to end	Day	15% 7% 2 6% 4 4 4 3 5% 6% 42%	3124
January	1st to 10th	Night	14% 7% 3 5% 3 3 3 3 5% 6% 46%	4109
	11th to 20th	Night	13% 7% 2 7% 5% 5% 4 4 5% 6% 42%	4120
	21st to end	Night	15% 7% 2 7% 4 4 4 3 5% 5% 44%	4532
February	1st to 10th	Night	16% 7% 2 6% 3 4 4 3 5% 5% 45%	2470
	11th to 20th	Night	17% 8% 3 6% 4 3 3 3 5% 5% 42%	2343
	21st to end	Night	16% 6% 2 6% 4 4 4 3 6% 6% 43%	1739
March	1st to 10th	Night	26% 11% 3 7% 4 3 3 2 4 5% 32%	3418
	11th to 20th	Night	11% 5% 2 6% 4 4 4 4 6% 7% 48%	3480
	21st to end	Night	16% 5% 1 5% 4 3 4 4 5% 6% 47%	3817
April	1st to 10th	Night	11% 5% 2 5% 3 3 4 3 6% 7% 49%	1962
	11th to 20th	Night	11% 5% 2 6% 4 4 5% 3 6% 6% 50%	1875
	21st to end	Night	10% 4 1 5% 3 4 4 4 6% 6% 51%	1900
May	1st to 10th	Night	7% 6% 3 7% 5% 5% 5% 4 6% 11% 41%	3012
	11th to 20th	Night	14% 9% 3 7% 5% 4 4 4 5% 7% 38%	2812
	21st to end	Night	7% 5% 2 5% 5% 4 5% 5% 8% 9% 45%	3079
June	1st to 10th	Night	10% 6% 3 6% 4 6% 6% 5% 7% 11% 37%	1710
	11th to 20th	Night	10% 6% 2 6% 4 5% 5% 4 8% 10% 40%	1710
	21st to end	Night	7% 5% 2 6% 6% 6% 6% 6% 9% 12% 35%	1710
July	1st to 10th	Night	8% 7% 2 8% 6% 6% 7% 6% 8% 10% 31%	2840
	11th to 20th	Night	11% 8% 4 8% 5% 5% 5% 5% 8% 12% 29%	2840
	21st to end	Night	13% 9% 4 9% 6% 5% 6% 5% 7% 9% 27%	3087
August	1st to 10th	Night	19% 10% 3 8% 5% 5% 5% 5% 6% 9% 25%	2825
	11th to 20th	Night	9% 6% 2 8% 5% 6% 6% 5% 8% 9% 35%	2966
	21st to end	Night	6% 4 2 7% 4 5% 5% 4 7% 11% 45%	3476
September	1st to 10th	Night	9% 5% 2 6% 4 5% 5% 5% 7% 9% 42%	1900
	11th to 20th	Night	13% 7% 2 6% 5% 5% 5% 4 6% 7% 41%	2000
	21st to end	Night	16% 8% 3 6% 4 4 4 4 5% 6% 39%	2146
October	1st to 10th	Night	13% 7% 2 6% 4 3 3 4 4 6% 47%	2280
	11th to 20th	Night	11% 6% 2 5% 3 3 3 3 4 6% 56%	2280
	21st to end	Night	10% 5% 2 4 3 3 4 3 4 6% 56%	2508
November	1st to 10th	Night	12% 6% 2 4 4 3 4 3 4 5% 53%	2341
	11th to 20th	Night	15% 7% 2 5% 2 3 3 3 6% 6% 49%	2287
	21st to end	Night	13% 6% 2 5% 4 3 3 3 5% 7% 50%	2394
December	1st to 10th	Night	16% 9% 3 6% 4 3 4 3 5% 6% 40%	2555
	11th to 20th	Night	16% 6% 2 5% 3 3 3 3 4 5% 49%	3042
	21st to end	Night	16% 7% 2 5% 3 4 4 3 4 5% 46%	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	37% 3 7% 22% 24% 6%	2837
	11th to 20th	Day	35% 3 6% 19% 26% 11%	2840
	21st to end	Day	43% 5% 6% 15% 21% 11%	3124
February	1st to 10th	Day	43% 3 9% 20% 20% 5%	1710
	11th to 20th	Day	43% 3 5% 18% 23% 8%	1729
	21st to end	Day	44% 4 9% 17% 17% 8%	1712
March	1st to 10th	Day	51% 4 7% 15% 14% 9%	3435
	11th to 20th	Day	31% 5% 8% 16% 28% 13%	3480
	21st to end	Day	44% 3 6% 19% 21% 6%	3815
April	1st to 10th	Day	31% 4 9% 22% 26% 7%	2216
	11th to 20th	Day	34% 4 9% 22% 22% 10%	2254
	21st to end	Day	35% 6% 10% 22% 22% 6%	2280
May	1st to 10th	Day	41% 9% 17% 20% 12% 2	3946
	11th to 20th	Day	48% 6% 8% 21% 15% 1	4085
	21st to end	Day	34% 9% 13% 21% 20% 3	4489
June	1st to 10th	Day	46% 7% 12% 21% 13% 1	2470
	11th to 20th	Day	40% 9% 14% 21% 13% 3	2470
	21st to end	Day	42% 10% 16% 20% 11% 2	2470
July	1st to 10th	Day	45% 13% 16% 19% 6% 2	4055
	11th to 20th	Day	51% 12% 20% 13% 4 1	4051
	21st to end	Day	50% 12% 14% 15% 8% 1	4324
August	1st to 10th	Day	63% 8% 13% 10% 4	4091
	11th to 20th	Day	45% 9% 13% 21% 11%	3868
	21st to end	Day	36% 7% 15% 31% 11% 1	4180
September	1st to 10th	Day	40% 8% 15% 17% 15% 5%	2280
	11th to 20th	Day	47% 7% 9% 14% 19% 4	2176
	21st to end	Day	46% 6% 10% 19% 16% 4	2033
October	1st to 10th	Day	39% 4 7% 20% 24% 6%	3160
	11th to 20th	Day	21% 3 5% 19% 26% 26%	3140
	21st to end	Day	27% 4 5% 21% 29% 14%	3428
November	1st to 10th	Day	34% 3 7% 19% 27% 10%	1957
	11th to 20th	Day	36% 3 6% 18% 27% 9%	1900
	21st to end	Day	36% 3 8% 21% 24% 8%	1782
December	1st to 10th	Day	46% 4 9% 20% 14% 6%	1568
	11th to 20th	Day	35% 3 5% 23% 24% 10%	2150
	21st to end	Day	42% 4 8% 21% 23% 2	3124
January	1st to 10th	Night	38% 3 6% 20% 26% 6%	4109
	11th to 20th	Night	42% 4 7% 17% 23% 7%	4120
	21st to end	Night	43% 5% 6% 14% 24% 8%	4532
February	1st to 10th	Night	41% 3 8% 18% 22% 7%	2470
	11th to 20th	Night	44% 4 7% 16% 21% 8%	2345
	21st to end	Night	40% 5% 8% 19% 19% 9%	1739
March	1st to 10th	Night	56% 5% 7% 13% 14% 6%	3418
	11th to 20th	Night	35% 6% 7% 13% 23% 16%	3480
	21st to end	Night	37% 6% 9% 22% 20% 6%	3817
April	1st to 10th	Night	34% 4 12% 17% 24% 9%	1962
	11th to 20th	Night	34% 5% 11% 21% 20% 9%	1875
	21st to end	Night	32% 6% 12% 25% 20% 5%	1900
May	1st to 10th	Night	36% 9% 17% 23% 13% 2	3042
	11th to 20th	Night	45% 7% 10% 22% 16% 1	2813
	21st to end	Night	31% 10% 17% 25% 16% 2	3087
June	1st to 10th	Night	41% 9% 17% 22% 10% 1	1710
	11th to 20th	Night	38% 8% 17% 25% 11% 1	1710
	21st to end	Night	38% 11% 18% 23% 8% 1	1710
July	1st to 10th	Night	44% 12% 19% 19% 5% 1	2795
	11th to 20th	Night	45% 12% 27% 12% 4 1	2786
	21st to end	Night	52% 10% 16% 15% 7%	2988
August	1st to 10th	Night	55% 8% 20% 13% 3	2814
	11th to 20th	Night	41% 12% 20% 20% 7%	2993
	21st to end	Night	31% 7% 16% 33% 11% 1	3476
September	1st to 10th	Night	37% 8% 18% 17% 15% 4	1900
	11th to 20th	Night	42% 8% 13% 19% 16% 3	2000
	21st to end	Night	46% 5% 12% 20% 14% 4	2146
October	1st to 10th	Night	40% 5% 7% 19% 23% 5%	3800
	11th to 20th	Night	21% 3 4 16% 25% 31%	3779
	21st to end	Night	25% 4 7% 24% 25% 15%	4120
November	1st to 10th	Night	34% 3 8% 18% 27% 11%	2341
	11th to 20th	Night	37% 3 8% 16% 24% 11%	2287
	21st to end	Night	34% 4 8% 22% 25% 7%	2394
December	1st to 10th	Night	45% 5% 11% 15% 19% 6%	2555
	11th to 20th	Night	39% 3 6% 20% 25% 7%	3044
	21st to end	Night	40% 3 7% 21% 25% 4	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	20% 25% 36% 17% 2	270
	11th to 20th	Day	21% 22% 37% 16% 4	270
	21st to end	Day	24% 23% 36% 13% 4	297
February	1st to 10th	Day	25% 20% 37% 16% 3	270
	11th to 20th	Day	31% 19% 36% 12% 2	327
	21st to end	Day	25% 19% 35% 19% 3	382
March	1st to 10th	Day	22% 18% 31% 21% 6% 1	460
	11th to 20th	Day	21% 24% 34% 15% 5% 1	460
	21st to end	Day	20% 18% 37% 17% 6% 2	506
April	1st to 10th	Day	22% 17% 31% 21% 7% 2	460
	11th to 20th	Day	15% 18% 29% 20% 13% 5%	452
	21st to end	Day	15% 13% 30% 24% 14% 3	460
May	1st to 10th	Day	12% 17% 31% 23% 12% 4	463
	11th to 20th	Day	16% 8% 24% 30% 16% 7%	487
	21st to end	Day	17% 4 18% 29% 22% 10%	529
June	1st to 10th	Day	15% 4 20% 32% 24% 4	490
	11th to 20th	Day	12% 3 20% 30% 23% 10%	490
	21st to end	Day	10% 3 18% 34% 26% 10%	490
July	1st to 10th	Day	12% 3 11% 30% 30% 15%	485
	11th to 20th	Day	14% 1 8% 36% 32% 10%	484
	21st to end	Day	8% 2 13% 36% 33% 8%	532
August	1st to 10th	Day	15% 5% 15% 26% 27% 13%	486
	11th to 20th	Day	15% 2 11% 28% 28% 15%	479
	21st to end	Day	14% 3 13% 32% 25% 14%	539
September	1st to 10th	Day	11% 2 17% 31% 22% 16%	490
	11th to 20th	Day	20% 4 12% 32% 23% 9%	490
	21st to end	Day	20% 4 21% 29% 17% 9%	490
October	1st to 10th	Day	19% 5% 23% 27% 18% 8%	490
	11th to 20th	Day	12% 12% 24% 30% 17% 4	490
	21st to end	Day	13% 10% 26% 27% 20% 4	539
November	1st to 10th	Day	17% 8% 28% 30% 12% 4	495
	11th to 20th	Day	18% 13% 36% 23% 9% 1	460
	21st to end	Day	13% 16% 36% 23% 11% 1	342
December	1st to 10th	Day	23% 15% 37% 19% 6%	202
	11th to 20th	Day	21% 17% 33% 19% 8% 2	270
	21st to end	Day	23% 16% 34% 16% 7% 4	297
January	1st to 10th	Night	20% 18% 31% 24% 7%	760
	11th to 20th	Night	18% 16% 28% 33% 6%	760
	21st to end	Night	20% 15% 34% 28% 3	836
February	1st to 10th	Night	21% 14% 33% 26% 6%	760
	11th to 20th	Night	24% 18% 34% 22% 2	743
	21st to end	Night	22% 16% 31% 26% 5%	628
March	1st to 10th	Night	19% 12% 36% 27% 5%	760
	11th to 20th	Night	18% 14% 37% 25% 6% 1	760
	21st to end	Night	17% 15% 36% 26% 6%	836
April	1st to 10th	Night	16% 17% 37% 24% 6%	760
	11th to 20th	Night	14% 13% 34% 28% 10%	751
	21st to end	Night	14% 9% 36% 33% 8% 1	760
May	1st to 10th	Night	11% 9% 37% 31% 11%	694
	11th to 20th	Night	17% 6% 23% 41% 12% 1	561
	21st to end	Night	12% 1 14% 42% 28% 3	617
June	1st to 10th	Night	12% 2 20% 44% 20% 2	570
	11th to 20th	Night	12% 2 16% 36% 28% 5%	570
	21st to end	Night	9% 2 18% 40% 28% 4	570
July	1st to 10th	Night	10% 2 10% 41% 33% 4	555
	11th to 20th	Night	10% 1 9% 40% 35% 6%	552
	21st to end	Night	9% 1 11% 46% 29% 4	624
August	1st to 10th	Night	14% 2 10% 38% 31% 5%	567
	11th to 20th	Night	13% 1 9% 38% 33% 6%	667
	21st to end	Night	12% 1 12% 35% 32% 7%	836
September	1st to 10th	Night	12% 2 11% 40% 32% 4	760
	11th to 20th	Night	16% 3 14% 35% 27% 4	760
	21st to end	Night	22% 3 17% 33% 22% 3	760
October	1st to 10th	Night	17% 4 20% 31% 24% 4	760
	11th to 20th	Night	15% 6% 27% 30% 20% 3	760
	21st to end	Night	13% 7% 25% 33% 19% 3	836
November	1st to 10th	Night	16% 7% 25% 33% 16% 3	780
	11th to 20th	Night	20% 10% 29% 27% 13% 1	763
	21st to end	Night	16% 11% 27% 30% 14% 2	760
December	1st to 10th	Night	21% 12% 26% 33% 7% 1	760
	11th to 20th	Night	19% 11% 26% 34% 10%	760
	21st to end	Night	21% 13% 27% 28% 9% 1	836

Page generated at 2024-11-08 06:44:47. Version ac07

Copyright © 2024 Attilla Danko.