Burk's Falls
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Burk's Falls clear sky chart from 2005-11-06 to 2024-04-03.

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	18% 12% 5% 8% 6% 3 4 4 4 6% 29%	78804
	Night	17% 14% 5% 9% 6% 3 4 4 4 5% 27%	81317
Transparency	Day	57% 4 10% 19% 9% 1	78505
	Night	59% 4 10% 17% 9% 1	81153
Seeing	Day	25% 15% 30% 19% 8% 2	14105
	Night	25% 13% 29% 25% 9% 1	23290

By Month

Percentage Cloud Cover NE (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% 23% 13% 14% 5% 2 2 2 4 4 16%	2208
	11th to 20th	Day	12% 16% 9% 19% 10% 3 5% 4 3 4 15%	2560
	21st to end	Day	17% 24% 9% 12% 6% 3 3 3 3 4 16%	3124
February	1st to 10th	Day	14% 18% 8% 14% 9% 3 4 3 4 4 18%	1710
	11th to 20th	Day	14% 17% 7% 12% 7% 4 4 4 4 5% 23%	1663
	21st to end	Day	16% 18% 6% 12% 8% 3 5% 3 4 4 21%	1418
March	1st to 10th	Day	16% 14% 5% 9% 8% 4 5% 4 3 6% 27%	2085
	11th to 20th	Day	12% 15% 6% 11% 7% 3 5% 5% 5% 5% 27%	2090
	21st to end	Day	17% 12% 5% 7% 6% 3 4 4 3 6% 35%	2299
April	1st to 10th	Day	20% 15% 6% 7% 5% 3 4 4 4 7% 27%	2164
	11th to 20th	Day	21% 11% 4 5% 5% 3 4 4 4 6% 34%	2240
	21st to end	Day	21% 13% 4 7% 5% 2 4 3 3 6% 33%	2340
May	1st to 10th	Day	20% 8% 3 6% 5% 3 4 5% 5% 8% 32%	2398
	11th to 20th	Day	18% 9% 3 6% 6% 2 4 5% 4 6% 35%	2478
	21st to end	Day	16% 6% 3 5% 5% 3 4 5% 5% 7% 40%	2725
June	1st to 10th	Day	20% 8% 3 6% 5% 3 4 5% 5% 8% 33%	2566
	11th to 20th	Day	16% 6% 4 6% 5% 3 6% 4 5% 7% 38%	2700
	21st to end	Day	19% 8% 3 6% 6% 4 5% 5% 6% 7% 32%	2700
July	1st to 10th	Day	13% 5% 3 5% 5% 4 5% 5% 5% 8% 42%	2700
	11th to 20th	Day	14% 6% 3 6% 6% 4 5% 5% 6% 8% 37%	2610
	21st to end	Day	14% 6% 3 6% 6% 3 5% 6% 7% 9% 36%	2672
August	1st to 10th	Day	14% 7% 3 6% 7% 3 5% 5% 6% 9% 36%	2327
	11th to 20th	Day	16% 6% 3 5% 7% 4 5% 5% 6% 7% 36%	2303
	21st to end	Day	15% 6% 3 7% 6% 4 5% 6% 6% 7% 35%	2502
September	1st to 10th	Day	16% 7% 3 6% 6% 3 4 4 6% 8% 38%	2160
	11th to 20th	Day	17% 7% 3 5% 4 3 5% 3 5% 6% 41%	2070
	21st to end	Day	24% 8% 3 6% 5% 3 5% 4 4 6% 33%	1936
October	1st to 10th	Day	21% 10% 3 6% 5% 3 5% 4 5% 6% 32%	1800
	11th to 20th	Day	28% 13% 3 8% 6% 3 4 3 4 5% 22%	1800
	21st to end	Day	32% 14% 6% 7% 5% 3 3 3 3 4 19%	1976
November	1st to 10th	Day	20% 14% 5% 7% 6% 3 4 4 5% 6% 24%	1504
	11th to 20th	Day	20% 18% 7% 8% 6% 3 4 3 4 6% 21%	1520
	21st to end	Day	24% 20% 8% 10% 7% 2 4 3 3 4 14%	1520
December	1st to 10th	Day	18% 25% 7% 10% 7% 2 4 4 4 5% 14%	1520
	11th to 20th	Day	19% 22% 7% 11% 7% 3 4 3 4 4 18%	1906
	21st to end	Day	22% 23% 8% 12% 7% 3 3 2 3 3 13%	2510
January	1st to 10th	Night	16% 21% 10% 15% 7% 4 4 4 4 4 12%	4748
	11th to 20th	Night	12% 17% 6% 16% 13% 5% 5% 4 4 5% 13%	4391
	21st to end	Night	15% 21% 11% 12% 7% 4 4 3 3 4 16%	4532
February	1st to 10th	Night	13% 18% 7% 11% 9% 4 5% 4 5% 5% 18%	2470
	11th to 20th	Night	12% 16% 8% 13% 7% 3 4 4 4 5% 24%	2403
	21st to end	Night	13% 18% 7% 11% 9% 4 5% 3 4 5% 21%	2032
March	1st to 10th	Night	13% 13% 6% 8% 7% 4 4 4 4 5% 31%	2080
	11th to 20th	Night	13% 14% 7% 8% 6% 3 4 4 4 5% 31%	2089
	21st to end	Night	15% 11% 4 6% 6% 3 4 4 4 6% 37%	2299
April	1st to 10th	Night	21% 14% 4 5% 5% 3 4 4 5% 5% 29%	1840
	11th to 20th	Night	18% 11% 4 6% 4 3 4 4 4 6% 37%	1686
	21st to end	Night	20% 11% 3 8% 7% 2 4 4 4 6% 31%	1620
May	1st to 10th	Night	17% 8% 3 5% 4 3 4 5% 5% 7% 37%	1562
	11th to 20th	Night	16% 6% 2 6% 4 2 5% 4 6% 7% 40%	1415
	21st to end	Night	12% 7% 3 5% 5% 3 4 5% 6% 8% 42%	1550
June	1st to 10th	Night	15% 8% 4 6% 6% 4 5% 5% 5% 7% 37%	1388
	11th to 20th	Night	16% 5% 2 4 6% 2 4 4 5% 8% 44%	1260
	21st to end	Night	14% 8% 3 5% 5% 3 4 5% 7% 7% 38%	1260
July	1st to 10th	Night	11% 5% 2 4 4 2 4 5% 5% 8% 49%	1260
	11th to 20th	Night	13% 5% 3 7% 5% 2 4 5% 6% 6% 45%	1347
	21st to end	Night	12% 6% 2 4 5% 3 5% 6% 6% 9% 42%	1641
August	1st to 10th	Night	12% 6% 2 5% 5% 3 4 4 5% 8% 45%	1611
	11th to 20th	Night	12% 6% 2 4 5% 3 4 6% 6% 7% 44%	1598
	21st to end	Night	16% 6% 2 6% 5% 4 4 4 5% 6% 41%	1834
September	1st to 10th	Night	14% 5% 2 4 5% 3 4 5% 6% 7% 45%	1800
	11th to 20th	Night	15% 6% 2 4 5% 3 4 4 5% 6% 46%	1888
	21st to end	Night	18% 7% 3 5% 5% 3 4 4 5% 7% 39%	2024
October	1st to 10th	Night	20% 9% 4 6% 5% 2 4 4 5% 6% 35%	2160
	11th to 20th	Night	26% 12% 3 7% 6% 3 5% 4 4 5% 24%	2160
	21st to end	Night	27% 17% 4 7% 5% 3 4 3 3 4 23%	2378
November	1st to 10th	Night	23% 14% 3 6% 5% 3 4 3 4 6% 29%	2574
	11th to 20th	Night	20% 14% 5% 8% 6% 3 4 4 4 6% 25%	2660
	21st to end	Night	23% 19% 6% 9% 7% 3 4 4 4 5% 16%	2660
December	1st to 10th	Night	20% 23% 9% 12% 7% 4 4 4 3 4 12%	2660
	11th to 20th	Night	19% 21% 8% 10% 7% 2 3 3 3 4 18%	3288
	21st to end	Night	22% 22% 8% 13% 8% 3 3 3 2 3 12%	5149

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	76% 2 9% 8% 5%	2209
	11th to 20th	Day	76% 3 6% 9% 5% 1	2560
	21st to end	Day	75% 3 5% 10% 6% 1	3124
February	1st to 10th	Day	72% 3 6% 14% 5% 1	1710
	11th to 20th	Day	64% 3 9% 13% 9% 2	1672
	21st to end	Day	69% 2 8% 13% 7%	1418
March	1st to 10th	Day	60% 3 12% 13% 10% 1	2088
	11th to 20th	Day	59% 4 9% 17% 10% 2	2090
	21st to end	Day	52% 3 9% 18% 14% 4	2299
April	1st to 10th	Day	58% 3 10% 17% 9% 2	2164
	11th to 20th	Day	53% 3 7% 23% 12% 1	2240
	21st to end	Day	55% 3 8% 16% 14% 3	2340
May	1st to 10th	Day	50% 5% 8% 20% 14% 3	2398
	11th to 20th	Day	49% 5% 8% 23% 14% 2	2482
	21st to end	Day	43% 6% 12% 22% 13% 3	2725
June	1st to 10th	Day	50% 4 10% 22% 13%	2566
	11th to 20th	Day	45% 4 10% 25% 14% 1	2700
	21st to end	Day	50% 5% 13% 20% 10% 1	2700
July	1st to 10th	Day	40% 6% 12% 28% 13% 1	2626
	11th to 20th	Day	43% 6% 12% 28% 11% 1	2530
	21st to end	Day	44% 6% 11% 28% 10%	2523
August	1st to 10th	Day	45% 6% 13% 25% 11% 1	2314
	11th to 20th	Day	46% 6% 14% 24% 9% 1	2303
	21st to end	Day	47% 7% 12% 24% 10%	2502
September	1st to 10th	Day	45% 5% 12% 27% 11%	2160
	11th to 20th	Day	44% 4 14% 28% 10% 1	2070
	21st to end	Day	54% 4 10% 26% 6%	1936
October	1st to 10th	Day	52% 6% 11% 20% 10% 1	1800
	11th to 20th	Day	66% 5% 10% 13% 6% 1	1800
	21st to end	Day	70% 3 9% 12% 6%	1976
November	1st to 10th	Day	61% 5% 13% 17% 5%	1504
	11th to 20th	Day	66% 5% 9% 13% 5% 1	1520
	21st to end	Day	75% 4 8% 10% 3 1	1520
December	1st to 10th	Day	74% 5% 9% 10% 2 1	1520
	11th to 20th	Day	72% 4 6% 12% 6%	1906
	21st to end	Day	79% 2 4 13% 3	2510
January	1st to 10th	Night	78% 3 6% 9% 3	4748
	11th to 20th	Night	74% 5% 8% 8% 4 1	4391
	21st to end	Night	75% 3 6% 9% 6% 1	4532
February	1st to 10th	Night	68% 4 9% 13% 5% 1	2470
	11th to 20th	Night	63% 3 9% 18% 7% 1	2405
	21st to end	Night	67% 3 9% 13% 6% 1	2032
March	1st to 10th	Night	55% 3 12% 15% 13% 2	2090
	11th to 20th	Night	56% 3 11% 17% 11% 2	2090
	21st to end	Night	50% 4 8% 21% 14% 3	2299
April	1st to 10th	Night	57% 4 8% 18% 11% 2	1840
	11th to 20th	Night	51% 3 8% 22% 15% 2	1686
	21st to end	Night	56% 5% 7% 15% 15% 3	1620
May	1st to 10th	Night	46% 4 10% 22% 16% 3	1562
	11th to 20th	Night	42% 5% 9% 23% 19% 2	1416
	21st to end	Night	38% 5% 16% 22% 16% 3	1551
June	1st to 10th	Night	48% 4 12% 21% 12% 3	1388
	11th to 20th	Night	38% 4 12% 27% 19%	1260
	21st to end	Night	43% 6% 16% 22% 12% 2	1260
July	1st to 10th	Night	31% 6% 13% 29% 19% 2	1225
	11th to 20th	Night	39% 5% 13% 29% 12% 2	1305
	21st to end	Night	38% 7% 15% 27% 12% 1	1550
August	1st to 10th	Night	37% 7% 17% 25% 13% 1	1600
	11th to 20th	Night	36% 7% 18% 27% 11% 1	1598
	21st to end	Night	43% 4 15% 26% 11% 1	1834
September	1st to 10th	Night	36% 8% 14% 27% 13% 1	1800
	11th to 20th	Night	38% 5% 15% 31% 10%	1888
	21st to end	Night	45% 4 14% 29% 9%	2024
October	1st to 10th	Night	50% 5% 10% 21% 13%	2160
	11th to 20th	Night	62% 5% 11% 17% 5%	2160
	21st to end	Night	68% 4 9% 13% 7%	2378
November	1st to 10th	Night	58% 4 13% 20% 6%	2574
	11th to 20th	Night	61% 5% 12% 16% 6% 1	2660
	21st to end	Night	71% 4 10% 11% 4	2660
December	1st to 10th	Night	78% 4 5% 9% 3	2660
	11th to 20th	Night	72% 4 6% 12% 5% 1	3288
	21st to end	Night	79% 3 6% 9% 3	5149

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	24% 26% 30% 14% 4 1	180
	11th to 20th	Day	26% 20% 33% 16% 4	202
	21st to end	Day	29% 17% 32% 17% 5%	297
February	1st to 10th	Day	29% 30% 32% 7% 2 1	270
	11th to 20th	Day	26% 27% 35% 12% 1	270
	21st to end	Day	38% 24% 31% 7%	225
March	1st to 10th	Day	25% 22% 34% 15% 3	458
	11th to 20th	Day	23% 21% 37% 14% 5% 1	460
	21st to end	Day	30% 18% 30% 15% 5% 1	506
April	1st to 10th	Day	29% 19% 31% 15% 5% 1	428
	11th to 20th	Day	34% 17% 24% 16% 6% 4	412
	21st to end	Day	31% 14% 33% 15% 6% 1	420
May	1st to 10th	Day	29% 14% 27% 19% 9% 2	423
	11th to 20th	Day	24% 15% 30% 17% 10% 4	447
	21st to end	Day	20% 18% 30% 19% 10% 3	485
June	1st to 10th	Day	24% 14% 31% 24% 6% 1	496
	11th to 20th	Day	19% 15% 32% 23% 9% 2	630
	21st to end	Day	23% 13% 34% 20% 9% 1	630
July	1st to 10th	Day	13% 11% 33% 30% 11% 1	621
	11th to 20th	Day	17% 12% 28% 28% 13% 3	529
	21st to end	Day	14% 10% 32% 30% 11% 3	488
August	1st to 10th	Day	18% 9% 28% 28% 12% 6%	446
	11th to 20th	Day	17% 7% 26% 24% 17% 9%	439
	21st to end	Day	20% 10% 31% 22% 14% 5%	495
September	1st to 10th	Day	18% 12% 31% 21% 12% 6%	450
	11th to 20th	Day	19% 8% 26% 27% 15% 4	450
	21st to end	Day	26% 12% 23% 22% 14% 3	450
October	1st to 10th	Day	27% 14% 25% 21% 10% 4	450
	11th to 20th	Day	32% 16% 33% 14% 3 2	450
	21st to end	Day	40% 16% 26% 15% 2	491
November	1st to 10th	Day	33% 19% 32% 14% 2	189
	11th to 20th	Day	32% 21% 34% 9% 4	180
	21st to end	Day	33% 19% 37% 7% 2 1	180
December	1st to 10th	Day	30% 17% 38% 14% 2	180
	11th to 20th	Day	38% 21% 27% 11% 2 1	180
	21st to end	Day	33% 23% 28% 13% 1 2	198
January	1st to 10th	Night	28% 17% 32% 17% 5% 1	950
	11th to 20th	Night	31% 15% 30% 18% 5%	776
	21st to end	Night	21% 12% 35% 24% 7% 1	836
February	1st to 10th	Night	24% 19% 34% 20% 3	760
	11th to 20th	Night	21% 19% 33% 22% 5%	743
	21st to end	Night	25% 21% 29% 23% 3	628
March	1st to 10th	Night	22% 19% 35% 20% 4	760
	11th to 20th	Night	22% 18% 35% 20% 5% 1	760
	21st to end	Night	23% 15% 29% 26% 7%	836
April	1st to 10th	Night	31% 12% 31% 21% 5%	729
	11th to 20th	Night	25% 14% 27% 23% 10% 1	622
	21st to end	Night	24% 12% 28% 25% 10% 1	540
May	1st to 10th	Night	23% 8% 26% 32% 10% 1	482
	11th to 20th	Night	21% 8% 31% 32% 8%	354
	21st to end	Night	14% 8% 37% 32% 8%	389
June	1st to 10th	Night	16% 9% 34% 32% 9%	360
	11th to 20th	Night	17% 8% 24% 39% 11%	360
	21st to end	Night	18% 7% 26% 34% 14% 1	360
July	1st to 10th	Night	14% 3 25% 42% 16% 1	350
	11th to 20th	Night	14% 6% 26% 35% 19%	348
	21st to end	Night	13% 6% 25% 40% 16% 1	461
August	1st to 10th	Night	17% 4 17% 38% 22% 2	537
	11th to 20th	Night	14% 4 18% 40% 22% 3	534
	21st to end	Night	19% 6% 25% 30% 17% 4	646
September	1st to 10th	Night	16% 6% 26% 32% 18% 2	720
	11th to 20th	Night	17% 8% 26% 28% 18% 3	720
	21st to end	Night	22% 8% 24% 28% 17% 3	720
October	1st to 10th	Night	24% 12% 26% 25% 12% 1	720
	11th to 20th	Night	30% 12% 30% 21% 7% 1	720
	21st to end	Night	37% 14% 28% 17% 4	792
November	1st to 10th	Night	32% 12% 26% 22% 7% 1	740
	11th to 20th	Night	28% 18% 28% 20% 6%	760
	21st to end	Night	36% 13% 29% 19% 3 1	760
December	1st to 10th	Night	33% 17% 30% 16% 5%	760
	11th to 20th	Night	31% 18% 32% 14% 3 1	760
	21st to end	Night	35% 15% 29% 18% 3	997

Page generated at 2024-03-31 06:08:53. Version ac07

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