Bunny Foo-Foo Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bunny Foo-Foo Observatory clear sky chart from 2005-11-06 to 2024-02-20.

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	14% 6% 2 5% 5% 3 4 5% 6% 8% 43%	78421
	Night	15% 6% 2 5% 5% 3 4 5% 5% 7% 44%	80768
Transparency	Day	39% 7% 11% 23% 16% 3	78131
	Night	39% 6% 11% 23% 17% 4	80577
Seeing	Day	19% 14% 28% 24% 11% 4	14002
	Night	18% 12% 30% 27% 12% 1	23663

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% 5% 2 4 4 2 3 4 5% 6% 48%	2585
	11th to 20th	Day	16% 10% 3 5% 5% 3 4 4 5% 5% 40%	2840
	21st to end	Day	18% 10% 3 6% 6% 3 4 3 5% 6% 36%	3124
February	1st to 10th	Day	15% 7% 2 6% 5% 3 5% 5% 5% 6% 40%	1710
	11th to 20th	Day	20% 6% 2 5% 4 3 4 3 6% 6% 42%	1724
	21st to end	Day	19% 8% 3 6% 6% 2 3 4 5% 6% 39%	1480
March	1st to 10th	Day	13% 6% 2 5% 4 2 4 4 4 6% 50%	1931
	11th to 20th	Day	18% 6% 2 5% 5% 3 4 4 4 6% 42%	1980
	21st to end	Day	17% 7% 3 6% 6% 3 4 5% 4 6% 39%	2219
April	1st to 10th	Day	13% 6% 3 5% 5% 3 5% 4 5% 7% 45%	2160
	11th to 20th	Day	13% 5% 2 5% 5% 3 4 4 5% 6% 48%	2134
	21st to end	Day	18% 6% 3 5% 4 3 5% 5% 5% 7% 42%	2160
May	1st to 10th	Day	14% 7% 2 5% 6% 2 4 6% 6% 8% 39%	2271
	11th to 20th	Day	17% 6% 2 5% 6% 3 5% 5% 6% 9% 36%	2414
	21st to end	Day	13% 5% 2 6% 5% 4 4 5% 6% 8% 42%	2725
June	1st to 10th	Day	11% 4 2 5% 5% 3 4 5% 6% 11% 43%	2520
	11th to 20th	Day	11% 5% 2 5% 5% 3 6% 6% 6% 9% 43%	2520
	21st to end	Day	10% 4 2 4 5% 4 5% 6% 8% 10% 42%	2520
July	1st to 10th	Day	9% 5% 2 6% 6% 4 5% 6% 7% 9% 41%	2520
	11th to 20th	Day	6% 3 2 5% 6% 4 5% 6% 8% 12% 44%	2448
	21st to end	Day	8% 5% 2 6% 6% 4 6% 8% 8% 10% 36%	2547
August	1st to 10th	Day	9% 6% 2 6% 6% 5% 6% 7% 7% 9% 36%	2327
	11th to 20th	Day	11% 5% 2 5% 6% 4 6% 6% 8% 9% 39%	2192
	21st to end	Day	10% 5% 2 5% 5% 3 6% 6% 7% 9% 41%	2376
September	1st to 10th	Day	14% 5% 2 4 5% 3 4 5% 5% 7% 45%	2160
	11th to 20th	Day	11% 6% 2 5% 4 3 4 4 6% 9% 48%	2160
	21st to end	Day	18% 7% 3 6% 4 3 5% 4 5% 7% 38%	1901
October	1st to 10th	Day	16% 5% 3 5% 4 2 4 4 5% 7% 47%	1800
	11th to 20th	Day	17% 4 2 4 4 2 3 3 4 6% 50%	1800
	21st to end	Day	13% 6% 3 5% 5% 3 3 3 4 7% 47%	1980
November	1st to 10th	Day	12% 5% 1 3 4 3 4 4 4 7% 53%	1754
	11th to 20th	Day	14% 6% 1 3 4 2 4 4 4 8% 51%	1710
	21st to end	Day	14% 6% 2 5% 4 2 3 4 5% 6% 50%	1527
December	1st to 10th	Day	16% 6% 2 6% 5% 2 4 5% 5% 8% 42%	1520
	11th to 20th	Day	16% 7% 2 5% 3 2 3 4 5% 6% 47%	1910
	21st to end	Day	17% 8% 3 5% 5% 3 5% 5% 6% 7% 37%	2772
January	1st to 10th	Night	15% 8% 2 5% 4 2 4 4 4 6% 46%	4356
	11th to 20th	Night	18% 7% 2 4 4 2 3 3 4 6% 46%	4120
	21st to end	Night	18% 10% 3 5% 4 2 3 3 3 6% 42%	4532
February	1st to 10th	Night	15% 7% 3 4 5% 3 5% 4 5% 7% 42%	2470
	11th to 20th	Night	20% 7% 3 5% 4 2 3 3 4 5% 44%	2325
	21st to end	Night	18% 8% 2 4 4 3 3 4 4 6% 43%	1776
March	1st to 10th	Night	14% 5% 2 5% 4 3 3 4 6% 6% 48%	2026
	11th to 20th	Night	18% 6% 2 5% 4 2 3 5% 5% 7% 43%	1980
	21st to end	Night	16% 6% 3 7% 4 2 4 4 5% 7% 42%	2136
April	1st to 10th	Night	15% 7% 2 5% 6% 3 4 4 6% 7% 42%	1800
	11th to 20th	Night	14% 5% 2 4 5% 2 4 4 5% 7% 48%	1775
	21st to end	Night	18% 5% 2 5% 3 2 5% 5% 6% 8% 42%	1800
May	1st to 10th	Night	14% 6% 4 5% 5% 3 5% 5% 6% 7% 40%	1704
	11th to 20th	Night	15% 6% 3 5% 6% 3 5% 4 6% 8% 39%	1477
	21st to end	Night	12% 6% 2 5% 5% 2 4 7% 6% 11% 39%	1550
June	1st to 10th	Night	10% 5% 2 4 5% 3 5% 5% 8% 10% 43%	1440
	11th to 20th	Night	12% 5% 3 5% 5% 3 5% 5% 7% 10% 40%	1440
	21st to end	Night	9% 4 2 5% 5% 4 5% 5% 8% 9% 43%	1440
July	1st to 10th	Night	8% 5% 2 6% 6% 4 6% 6% 7% 9% 41%	1440
	11th to 20th	Night	6% 4 3 6% 4 3 5% 7% 5% 11% 46%	1508
	21st to end	Night	8% 4 2 5% 5% 4 6% 7% 10% 11% 39%	1771
August	1st to 10th	Night	8% 4 2 5% 5% 4 6% 7% 7% 10% 41%	1611
	11th to 20th	Night	10% 6% 3 7% 6% 3 6% 6% 8% 8% 37%	1691
	21st to end	Night	10% 5% 3 6% 5% 3 5% 5% 6% 9% 42%	1980
September	1st to 10th	Night	14% 5% 2 5% 4 3 5% 4 5% 8% 45%	1800
	11th to 20th	Night	9% 6% 2 5% 4 2 4 5% 5% 8% 49%	1800
	21st to end	Night	17% 8% 2 6% 5% 2 4 5% 5% 7% 39%	2053
October	1st to 10th	Night	17% 6% 2 5% 4 2 4 4 4 6% 46%	2160
	11th to 20th	Night	16% 5% 2 5% 4 2 3 4 4 6% 50%	2160
	21st to end	Night	15% 4 2 4 4 2 4 4 4 7% 48%	2376
November	1st to 10th	Night	13% 5% 2 4 4 2 3 4 4 6% 53%	2322
	11th to 20th	Night	16% 6% 2 3 4 2 4 4 4 7% 49%	2470
	21st to end	Night	13% 4 2 4 4 2 4 5% 6% 7% 49%	2650
December	1st to 10th	Night	17% 8% 3 5% 4 2 4 4 5% 6% 42%	2660
	11th to 20th	Night	17% 5% 3 5% 4 3 4 4 4 7% 44%	3285
	21st to end	Night	16% 7% 3 5% 5% 3 5% 6% 5% 7% 37%	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	37% 4 7% 32% 16% 4	2586
	11th to 20th	Day	45% 4 9% 20% 16% 5%	2840
	21st to end	Day	48% 7% 10% 21% 12% 2	3124
February	1st to 10th	Day	44% 6% 11% 25% 13% 2	1710
	11th to 20th	Day	43% 4 8% 24% 19% 3	1733
	21st to end	Day	47% 5% 11% 18% 16% 4	1480
March	1st to 10th	Day	36% 4 11% 25% 20% 3	1931
	11th to 20th	Day	43% 5% 9% 19% 18% 6%	1980
	21st to end	Day	46% 5% 9% 19% 17% 4	2219
April	1st to 10th	Day	38% 6% 10% 21% 19% 6%	2160
	11th to 20th	Day	36% 6% 9% 22% 21% 7%	2134
	21st to end	Day	42% 5% 10% 21% 17% 5%	2160
May	1st to 10th	Day	41% 7% 13% 20% 16% 3	2271
	11th to 20th	Day	44% 7% 13% 21% 14% 2	2418
	21st to end	Day	39% 8% 13% 26% 12% 2	2725
June	1st to 10th	Day	35% 9% 13% 26% 15% 1	2520
	11th to 20th	Day	36% 10% 13% 22% 16% 2	2520
	21st to end	Day	33% 10% 15% 24% 17% 2	2520
July	1st to 10th	Day	38% 9% 13% 21% 16% 3	2450
	11th to 20th	Day	31% 9% 16% 27% 15% 2	2373
	21st to end	Day	38% 11% 13% 20% 17% 1	2405
August	1st to 10th	Day	41% 11% 13% 24% 11% 1	2314
	11th to 20th	Day	38% 10% 14% 21% 14% 1	2192
	21st to end	Day	36% 9% 15% 23% 14% 4	2376
September	1st to 10th	Day	38% 7% 13% 20% 18% 4	2160
	11th to 20th	Day	34% 7% 9% 26% 21% 4	2160
	21st to end	Day	45% 6% 9% 20% 17% 3	1901
October	1st to 10th	Day	38% 7% 10% 25% 19% 3	1800
	11th to 20th	Day	36% 4 8% 26% 22% 4	1800
	21st to end	Day	37% 5% 7% 26% 22% 3	1980
November	1st to 10th	Day	32% 5% 10% 28% 21% 4	1754
	11th to 20th	Day	34% 4 10% 25% 22% 5%	1710
	21st to end	Day	37% 4 9% 28% 19% 3	1527
December	1st to 10th	Day	42% 5% 12% 25% 12% 3	1520
	11th to 20th	Day	39% 5% 9% 31% 13% 4	1906
	21st to end	Day	44% 6% 12% 25% 12% 1	2772
January	1st to 10th	Night	39% 5% 7% 26% 18% 4	4356
	11th to 20th	Night	41% 5% 8% 24% 19% 3	4120
	21st to end	Night	46% 4 7% 26% 17% 1	4532
February	1st to 10th	Night	42% 5% 11% 25% 16% 2	2470
	11th to 20th	Night	44% 3 8% 20% 19% 5%	2327
	21st to end	Night	43% 3 10% 22% 17% 5%	1776
March	1st to 10th	Night	37% 5% 9% 26% 20% 3	2026
	11th to 20th	Night	41% 6% 10% 21% 18% 4	1980
	21st to end	Night	42% 6% 10% 20% 16% 6%	2136
April	1st to 10th	Night	42% 4 10% 19% 20% 5%	1800
	11th to 20th	Night	36% 5% 11% 21% 21% 6%	1775
	21st to end	Night	41% 5% 10% 24% 15% 5%	1800
May	1st to 10th	Night	41% 7% 12% 22% 14% 4	1704
	11th to 20th	Night	42% 8% 12% 19% 16% 3	1478
	21st to end	Night	38% 8% 17% 23% 13% 2	1551
June	1st to 10th	Night	34% 9% 12% 26% 17% 2	1440
	11th to 20th	Night	38% 7% 15% 24% 13% 3	1440
	21st to end	Night	34% 9% 15% 20% 19% 3	1440
July	1st to 10th	Night	37% 10% 17% 19% 13% 4	1400
	11th to 20th	Night	31% 10% 16% 25% 16% 2	1460
	21st to end	Night	32% 10% 16% 27% 14% 1	1672
August	1st to 10th	Night	36% 10% 16% 22% 14% 1	1600
	11th to 20th	Night	42% 10% 14% 21% 12% 2	1691
	21st to end	Night	38% 8% 13% 23% 15% 3	1980
September	1st to 10th	Night	38% 7% 11% 22% 17% 6%	1800
	11th to 20th	Night	32% 7% 9% 26% 22% 4	1800
	21st to end	Night	43% 7% 9% 19% 17% 4	2053
October	1st to 10th	Night	40% 6% 9% 23% 19% 4	2160
	11th to 20th	Night	36% 5% 8% 26% 21% 3	2160
	21st to end	Night	36% 5% 9% 24% 22% 4	2376
November	1st to 10th	Night	33% 5% 9% 26% 21% 6%	2322
	11th to 20th	Night	37% 4 9% 21% 23% 6%	2470
	21st to end	Night	33% 5% 11% 26% 21% 4	2650
December	1st to 10th	Night	43% 5% 11% 24% 15% 3	2660
	11th to 20th	Night	40% 4 10% 23% 19% 4	3288
	21st to end	Night	44% 7% 13% 23% 11% 1	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	28% 25% 30% 13% 4 1	200
	11th to 20th	Day	32% 24% 28% 14% 1	270
	21st to end	Day	23% 30% 33% 12% 2	297
February	1st to 10th	Day	23% 27% 37% 10% 3	270
	11th to 20th	Day	35% 23% 32% 9% 1	337
	21st to end	Day	32% 24% 29% 14% 2	346
March	1st to 10th	Day	21% 26% 34% 17% 2	420
	11th to 20th	Day	28% 21% 31% 15% 4 1	420
	21st to end	Day	24% 18% 34% 18% 4 1	462
April	1st to 10th	Day	22% 23% 32% 17% 5% 1	420
	11th to 20th	Day	18% 19% 31% 19% 9% 3	412
	21st to end	Day	25% 16% 35% 17% 6% 1	420
May	1st to 10th	Day	26% 19% 26% 18% 10% 2	423
	11th to 20th	Day	20% 17% 30% 22% 9% 2	447
	21st to end	Day	18% 8% 26% 27% 17% 4	485
June	1st to 10th	Day	12% 10% 29% 27% 18% 4	450
	11th to 20th	Day	14% 9% 30% 27% 15% 4	450
	21st to end	Day	11% 8% 31% 31% 16% 3	450
July	1st to 10th	Day	12% 3 22% 33% 21% 9%	445
	11th to 20th	Day	4 3 18% 44% 23% 8%	444
	21st to end	Day	10% 3 25% 35% 20% 7%	488
August	1st to 10th	Day	11% 5% 22% 33% 22% 7%	446
	11th to 20th	Day	13% 3 18% 35% 22% 8%	439
	21st to end	Day	10% 4 21% 32% 20% 12%	495
September	1st to 10th	Day	16% 6% 21% 26% 16% 14%	450
	11th to 20th	Day	14% 5% 22% 34% 14% 10%	450
	21st to end	Day	23% 12% 25% 24% 11% 4	450
October	1st to 10th	Day	20% 9% 24% 26% 17% 5%	450
	11th to 20th	Day	17% 14% 29% 26% 13% 2	450
	21st to end	Day	18% 14% 37% 20% 9% 2	495
November	1st to 10th	Day	17% 15% 34% 22% 10% 3	406
	11th to 20th	Day	19% 18% 31% 22% 8% 2	370
	21st to end	Day	23% 20% 31% 14% 11% 1	187
December	1st to 10th	Day	19% 24% 38% 12% 6% 1	180
	11th to 20th	Day	26% 22% 29% 19% 4	180
	21st to end	Day	27% 19% 30% 20% 4 1	198
January	1st to 10th	Night	21% 21% 38% 16% 4	760
	11th to 20th	Night	24% 17% 32% 22% 4	760
	21st to end	Night	20% 20% 38% 20% 2	836
February	1st to 10th	Night	21% 17% 35% 24% 3	760
	11th to 20th	Night	26% 24% 35% 14% 2	742
	21st to end	Night	24% 21% 35% 17% 2	592
March	1st to 10th	Night	20% 17% 38% 22% 2	720
	11th to 20th	Night	23% 17% 37% 17% 6%	720
	21st to end	Night	20% 17% 41% 18% 4 1	792
April	1st to 10th	Night	20% 22% 36% 18% 4	720
	11th to 20th	Night	17% 15% 35% 27% 6%	711
	21st to end	Night	23% 12% 32% 25% 8%	720
May	1st to 10th	Night	19% 12% 33% 26% 10% 1	624
	11th to 20th	Night	18% 8% 33% 33% 8%	416
	21st to end	Night	15% 4 25% 37% 17% 1	389
June	1st to 10th	Night	11% 4 27% 36% 20% 1	360
	11th to 20th	Night	13% 5% 23% 42% 17% 1	360
	21st to end	Night	11% 2 27% 43% 15% 1	360
July	1st to 10th	Night	11% 2 21% 39% 26% 1	350
	11th to 20th	Night	6% 2 14% 46% 28% 4	416
	21st to end	Night	9% 1 23% 37% 27% 3	591
August	1st to 10th	Night	9% 2 15% 43% 28% 3	537
	11th to 20th	Night	12% 2 18% 41% 24% 2	627
	21st to end	Night	13% 2 18% 35% 27% 5%	792
September	1st to 10th	Night	18% 3 16% 33% 26% 4	720
	11th to 20th	Night	12% 3 17% 39% 26% 4	720
	21st to end	Night	20% 7% 24% 29% 18% 1	720
October	1st to 10th	Night	19% 7% 22% 30% 17% 5%	720
	11th to 20th	Night	17% 12% 26% 28% 16% 1	720
	21st to end	Night	18% 12% 33% 24% 11% 1	792
November	1st to 10th	Night	15% 10% 35% 27% 10% 2	740
	11th to 20th	Night	20% 16% 29% 25% 9% 1	760
	21st to end	Night	17% 17% 31% 25% 9% 1	760
December	1st to 10th	Night	22% 16% 32% 21% 8% 1	760
	11th to 20th	Night	19% 16% 38% 22% 5%	760
	21st to end	Night	21% 14% 34% 28% 3	836

Page generated at 2024-02-17 06:28:37. Version ac07

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