Breezy Point Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Breezy Point Observatory clear sky chart from 2005-11-06 to 2024-11-05.

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	16% 9% 3 7% 5% 4 4 4 6% 7% 35%	101229
	Night	16% 10% 3 7% 5% 4 4 3 5% 7% 36%	97762
Transparency	Day	46% 6% 10% 22% 14% 2	104931
	Night	46% 6% 10% 21% 15% 3	102199
Seeing	Day	21% 13% 26% 22% 13% 5%	15016
	Night	21% 10% 25% 28% 15% 2	25086

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	19% 19% 7% 10% 5% 4 4 3 4 5% 20%	2836
	11th to 20th	Day	16% 19% 9% 13% 7% 3 2 2 3 3 22%	2840
	21st to end	Day	25% 20% 6% 8% 6% 4 3 2 4 4 18%	3124
February	1st to 10th	Day	22% 14% 5% 9% 5% 3 2 3 4 5% 29%	1710
	11th to 20th	Day	20% 14% 4 10% 4 5% 3 3 4 5% 27%	1779
	21st to end	Day	23% 13% 4 7% 4 3 4 3 3 5% 31%	1570
March	1st to 10th	Day	22% 15% 4 8% 5% 4 3 3 4 5% 28%	3375
	11th to 20th	Day	15% 7% 3 6% 4 4 5% 3 5% 7% 39%	3480
	21st to end	Day	20% 9% 3 7% 5% 4 4 4 5% 7% 33%	3815
April	1st to 10th	Day	15% 11% 3 7% 5% 4 4 4 5% 7% 35%	2092
	11th to 20th	Day	17% 9% 2 6% 4 3 3 3 5% 7% 40%	2374
	21st to end	Day	18% 8% 3 6% 6% 4 4 3 6% 6% 36%	2470
May	1st to 10th	Day	21% 10% 3 9% 5% 5% 5% 4 6% 7% 26%	4082
	11th to 20th	Day	19% 9% 3 8% 4 4 4 4 5% 7% 33%	4081
	21st to end	Day	11% 6% 2 6% 5% 6% 6% 5% 8% 10% 36%	4476
June	1st to 10th	Day	13% 6% 2 6% 5% 4 5% 4 7% 9% 39%	2470
	11th to 20th	Day	10% 6% 3 7% 5% 5% 5% 5% 7% 9% 38%	2470
	21st to end	Day	11% 6% 2 6% 5% 5% 5% 4 7% 11% 37%	2470
July	1st to 10th	Day	9% 5% 3 7% 5% 5% 6% 5% 6% 8% 42%	4120
	11th to 20th	Day	9% 4 2 6% 4 5% 5% 5% 7% 9% 42%	4120
	21st to end	Day	16% 9% 3 7% 5% 5% 5% 4 6% 8% 31%	4466
August	1st to 10th	Day	9% 6% 2 7% 6% 6% 6% 5% 7% 10% 34%	4104
	11th to 20th	Day	9% 7% 3 7% 5% 5% 5% 5% 7% 9% 38%	4044
	21st to end	Day	6% 3 1 5% 4 5% 5% 4 6% 8% 50%	4414
September	1st to 10th	Day	14% 5% 2 5% 4 4 4 5% 5% 7% 46%	2124
	11th to 20th	Day	10% 6% 2 6% 4 4 4 3 6% 7% 47%	2090
	21st to end	Day	19% 6% 2 6% 4 4 4 3 4 6% 40%	2090
October	1st to 10th	Day	13% 6% 2 6% 3 4 5% 4 5% 8% 45%	1986
	11th to 20th	Day	17% 6% 2 6% 4 4 4 3 5% 6% 44%	1900
	21st to end	Day	20% 7% 2 6% 3 4 4 3 4 6% 41%	2090
November	1st to 10th	Day	12% 5% 2 6% 3 4 3 3 4 5% 51%	1760
	11th to 20th	Day	16% 12% 3 7% 4 4 4 3 5% 6% 37%	1710
	21st to end	Day	18% 10% 3 7% 5% 4 4 3 5% 5% 36%	1710
December	1st to 10th	Day	25% 16% 3 8% 5% 4 3 3 4 5% 24%	1710
	11th to 20th	Day	21% 16% 6% 9% 3 3 2 3 5% 5% 28%	2153
	21st to end	Day	21% 19% 5% 10% 5% 5% 4 4 6% 6% 16%	3124
January	1st to 10th	Night	16% 19% 5% 12% 6% 5% 4 3 4 4 21%	4109
	11th to 20th	Night	20% 16% 6% 13% 4 4 4 3 3 4 23%	4120
	21st to end	Night	27% 16% 5% 9% 6% 4 3 2 3 4 22%	4532
February	1st to 10th	Night	21% 12% 4 9% 5% 4 3 3 4 5% 29%	2470
	11th to 20th	Night	22% 12% 4 8% 5% 4 5% 2 4 5% 29%	2284
	21st to end	Night	23% 15% 4 6% 3 5% 4 3 4 5% 28%	1884
March	1st to 10th	Night	21% 12% 3 6% 4 4 4 3 4 7% 32%	3466
	11th to 20th	Night	14% 10% 3 7% 5% 4 4 3 5% 8% 37%	3480
	21st to end	Night	17% 9% 2 7% 4 3 4 3 5% 6% 40%	3817
April	1st to 10th	Night	16% 11% 3 6% 4 4 4 3 5% 7% 37%	2087
	11th to 20th	Night	15% 7% 2 6% 3 4 5% 3 5% 9% 40%	1771
	21st to end	Night	15% 8% 2 8% 4 4 4 3 6% 6% 40%	1710
May	1st to 10th	Night	25% 10% 4 8% 5% 4 4 3 4 6% 26%	2813
	11th to 20th	Night	20% 8% 3 7% 4 4 4 4 4 8% 36%	2812
	21st to end	Night	11% 7% 2 6% 4 4 4 4 6% 8% 42%	3079
June	1st to 10th	Night	11% 5% 2 5% 5% 4 5% 4 7% 9% 44%	1710
	11th to 20th	Night	9% 5% 2 6% 5% 4 5% 5% 7% 11% 41%	1710
	21st to end	Night	9% 6% 2 5% 4 4 4 4 7% 10% 44%	1710
July	1st to 10th	Night	9% 6% 3 6% 4 5% 5% 4 7% 9% 42%	2840
	11th to 20th	Night	9% 6% 2 6% 5% 4 5% 5% 6% 9% 42%	2840
	21st to end	Night	11% 8% 3 8% 5% 5% 5% 5% 6% 7% 37%	3087
August	1st to 10th	Night	10% 7% 3 8% 6% 5% 6% 4 6% 9% 36%	2825
	11th to 20th	Night	11% 7% 2 7% 5% 5% 5% 3 5% 8% 42%	2785
	21st to end	Night	6% 3 2 5% 5% 5% 4 4 7% 10% 49%	3210
September	1st to 10th	Night	12% 4 1 5% 4 4 4 4 5% 7% 51%	2052
	11th to 20th	Night	9% 4 2 5% 4 4 3 4 5% 6% 54%	2090
	21st to end	Night	16% 6% 2 6% 4 4 4 4 5% 6% 43%	2090
October	1st to 10th	Night	12% 5% 2 5% 4 4 4 3 5% 7% 49%	2194
	11th to 20th	Night	15% 6% 2 6% 3 3 4 4 4 6% 47%	2280
	21st to end	Night	21% 6% 3 6% 4 4 3 2 4 5% 43%	2508
November	1st to 10th	Night	12% 6% 2 5% 4 4 4 3 4 5% 50%	2413
	11th to 20th	Night	17% 10% 3 6% 4 4 4 4 4 7% 37%	2470
	21st to end	Night	18% 11% 3 7% 4 4 5% 3 4 6% 36%	2470
December	1st to 10th	Night	23% 14% 4 9% 5% 4 3 3 4 5% 26%	2470
	11th to 20th	Night	18% 15% 6% 9% 4 3 4 4 4 5% 28%	3042
	21st to end	Night	19% 18% 5% 9% 5% 5% 4 3 5% 6% 20%	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	65% 4 12% 13% 5%	2837
	11th to 20th	Day	69% 3 8% 15% 5%	2840
	21st to end	Day	71% 4 7% 14% 4 1	3124
February	1st to 10th	Day	59% 3 10% 18% 9% 1	1710
	11th to 20th	Day	60% 4 9% 16% 9% 1	1788
	21st to end	Day	57% 4 9% 19% 10% 1	1570
March	1st to 10th	Day	60% 4 8% 20% 7% 1	3375
	11th to 20th	Day	43% 5% 10% 27% 15% 1	3480
	21st to end	Day	49% 6% 9% 22% 12% 1	3815
April	1st to 10th	Day	48% 6% 10% 19% 13% 4	2092
	11th to 20th	Day	45% 5% 9% 20% 17% 4	2374
	21st to end	Day	48% 7% 11% 20% 12% 3	2470
May	1st to 10th	Day	56% 7% 9% 19% 9% 1	4120
	11th to 20th	Day	49% 7% 10% 19% 14% 1	4085
	21st to end	Day	38% 9% 16% 18% 15% 4	4489
June	1st to 10th	Day	40% 8% 12% 22% 16% 1	2470
	11th to 20th	Day	39% 9% 13% 21% 16% 2	2470
	21st to end	Day	40% 8% 14% 22% 13% 2	2470
July	1st to 10th	Day	38% 9% 11% 24% 15% 3	4055
	11th to 20th	Day	35% 7% 12% 30% 15% 1	4051
	21st to end	Day	49% 7% 11% 15% 16% 2	4324
August	1st to 10th	Day	41% 9% 13% 26% 10%	4091
	11th to 20th	Day	38% 9% 8% 28% 16% 1	4083
	21st to end	Day	30% 7% 13% 28% 20% 2	4414
September	1st to 10th	Day	37% 5% 10% 20% 22% 6%	2124
	11th to 20th	Day	35% 6% 10% 25% 20% 3	2090
	21st to end	Day	45% 4 10% 20% 19% 1	2090
October	1st to 10th	Day	27% 4 9% 26% 32% 2	3298
	11th to 20th	Day	33% 4 11% 26% 20% 5%	3140
	21st to end	Day	32% 3 11% 30% 22% 2	3428
November	1st to 10th	Day	35% 5% 9% 29% 18% 4	1760
	11th to 20th	Day	48% 4 7% 21% 16% 3	1710
	21st to end	Day	50% 5% 10% 21% 14% 1	1710
December	1st to 10th	Day	64% 4 8% 19% 4 1	1710
	11th to 20th	Day	60% 4 9% 18% 9%	2150
	21st to end	Day	68% 6% 11% 12% 4	3124
January	1st to 10th	Night	65% 5% 9% 14% 6% 1	4109
	11th to 20th	Night	65% 4 11% 14% 5% 1	4120
	21st to end	Night	67% 4 7% 17% 4 1	4532
February	1st to 10th	Night	57% 5% 10% 18% 9% 1	2470
	11th to 20th	Night	59% 4 7% 17% 12% 1	2286
	21st to end	Night	58% 5% 9% 16% 9% 3	1884
March	1st to 10th	Night	53% 4 8% 22% 13% 1	3466
	11th to 20th	Night	44% 5% 11% 25% 15% 1	3480
	21st to end	Night	45% 4 8% 26% 15% 2	3817
April	1st to 10th	Night	47% 5% 9% 20% 16% 3	2087
	11th to 20th	Night	41% 5% 12% 20% 16% 6%	1771
	21st to end	Night	44% 6% 10% 20% 17% 2	1710
May	1st to 10th	Night	57% 7% 9% 15% 10% 2	2840
	11th to 20th	Night	45% 8% 11% 22% 12% 2	2813
	21st to end	Night	36% 8% 14% 25% 13% 5%	3087
June	1st to 10th	Night	34% 8% 12% 26% 18% 3	1710
	11th to 20th	Night	35% 10% 15% 19% 19% 2	1710
	21st to end	Night	34% 8% 15% 24% 18% 2	1710
July	1st to 10th	Night	38% 7% 10% 23% 17% 4	2795
	11th to 20th	Night	36% 8% 13% 26% 15% 2	2786
	21st to end	Night	43% 9% 8% 21% 13% 5%	2988
August	1st to 10th	Night	43% 8% 14% 25% 10% 1	2814
	11th to 20th	Night	40% 7% 9% 21% 23% 1	2812
	21st to end	Night	29% 6% 13% 28% 22% 3	3210
September	1st to 10th	Night	32% 6% 12% 21% 21% 8%	2052
	11th to 20th	Night	30% 6% 12% 24% 25% 3	2090
	21st to end	Night	40% 7% 10% 20% 22% 2	2090
October	1st to 10th	Night	29% 4 8% 26% 28% 5%	3662
	11th to 20th	Night	30% 4 9% 24% 24% 9%	3779
	21st to end	Night	32% 3 6% 27% 26% 5%	4120
November	1st to 10th	Night	37% 4 10% 21% 22% 5%	2413
	11th to 20th	Night	47% 4 9% 19% 18% 3	2470
	21st to end	Night	50% 5% 9% 22% 13% 1	2470
December	1st to 10th	Night	61% 5% 8% 19% 6% 1	2470
	11th to 20th	Night	58% 5% 10% 18% 8% 1	3044
	21st to end	Night	65% 5% 10% 15% 6%	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	30% 22% 33% 11% 3 1	270
	11th to 20th	Day	37% 25% 30% 8% 1	270
	21st to end	Day	33% 26% 28% 10% 3	297
February	1st to 10th	Day	35% 21% 28% 12% 4	270
	11th to 20th	Day	40% 26% 27% 4 1 1	270
	21st to end	Day	35% 23% 33% 9%	225
March	1st to 10th	Day	30% 19% 31% 15% 4	422
	11th to 20th	Day	28% 21% 30% 15% 6% 1	460
	21st to end	Day	31% 16% 31% 18% 3 1	506
April	1st to 10th	Day	27% 20% 27% 18% 7% 1	460
	11th to 20th	Day	26% 17% 27% 19% 7% 4	452
	21st to end	Day	28% 17% 29% 17% 7% 2	460
May	1st to 10th	Day	26% 15% 32% 16% 8% 4	463
	11th to 20th	Day	21% 11% 31% 20% 12% 4	487
	21st to end	Day	12% 10% 26% 27% 16% 7%	529
June	1st to 10th	Day	16% 9% 25% 28% 18% 6%	490
	11th to 20th	Day	14% 8% 24% 31% 18% 6%	490
	21st to end	Day	12% 8% 30% 28% 16% 6%	490
July	1st to 10th	Day	12% 5% 24% 24% 19% 17%	485
	11th to 20th	Day	10% 6% 23% 32% 19% 9%	484
	21st to end	Day	16% 5% 21% 28% 20% 10%	532
August	1st to 10th	Day	12% 3 21% 33% 21% 10%	486
	11th to 20th	Day	15% 6% 23% 27% 20% 10%	479
	21st to end	Day	9% 3 21% 33% 22% 11%	539
September	1st to 10th	Day	14% 5% 19% 27% 25% 11%	490
	11th to 20th	Day	11% 4 15% 30% 28% 12%	490
	21st to end	Day	23% 8% 22% 23% 18% 4	490
October	1st to 10th	Day	14% 7% 27% 26% 21% 5%	490
	11th to 20th	Day	21% 12% 27% 25% 12% 3	490
	21st to end	Day	25% 13% 29% 23% 8% 2	539
November	1st to 10th	Day	19% 14% 33% 22% 9% 2	334
	11th to 20th	Day	29% 17% 27% 19% 7% 1	270
	21st to end	Day	22% 23% 32% 18% 4 1	270
December	1st to 10th	Day	32% 19% 30% 15% 3 1	270
	11th to 20th	Day	28% 22% 31% 14% 4 1	270
	21st to end	Day	34% 21% 27% 13% 4	297
January	1st to 10th	Night	26% 20% 30% 19% 4	760
	11th to 20th	Night	32% 18% 28% 19% 3	760
	21st to end	Night	28% 18% 30% 21% 3	836
February	1st to 10th	Night	29% 12% 30% 28% 1	760
	11th to 20th	Night	32% 18% 30% 19% 1	743
	21st to end	Night	32% 14% 31% 20% 2	628
March	1st to 10th	Night	26% 14% 29% 24% 6%	760
	11th to 20th	Night	27% 16% 26% 21% 8% 1	760
	21st to end	Night	27% 14% 31% 22% 6%	836
April	1st to 10th	Night	25% 15% 30% 23% 6%	760
	11th to 20th	Night	18% 14% 33% 24% 11% 1	647
	21st to end	Night	18% 10% 36% 30% 6%	570
May	1st to 10th	Night	19% 9% 29% 29% 14% 1	570
	11th to 20th	Night	19% 6% 28% 29% 17% 2	561
	21st to end	Night	13% 3 22% 31% 27% 4	617
June	1st to 10th	Night	11% 4 25% 35% 24% 2	570
	11th to 20th	Night	10% 3 20% 38% 26% 2	570
	21st to end	Night	12% 4 20% 39% 24% 2	570
July	1st to 10th	Night	13% 3 15% 35% 30% 5%	555
	11th to 20th	Night	8% 3 20% 34% 32% 4	552
	21st to end	Night	11% 3 15% 33% 33% 5%	624
August	1st to 10th	Night	9% 2 14% 37% 35% 2	567
	11th to 20th	Night	12% 2 13% 37% 30% 6%	564
	21st to end	Night	11% 1 15% 33% 33% 6%	674
September	1st to 10th	Night	13% 3 16% 33% 30% 5%	760
	11th to 20th	Night	11% 3 17% 32% 33% 5%	760
	21st to end	Night	19% 5% 20% 32% 20% 3	760
October	1st to 10th	Night	15% 4 22% 30% 26% 3	760
	11th to 20th	Night	19% 7% 28% 29% 16% 1	760
	21st to end	Night	23% 10% 24% 31% 11% 1	836
November	1st to 10th	Night	16% 10% 26% 32% 15% 1	760
	11th to 20th	Night	24% 14% 24% 28% 9% 1	760
	21st to end	Night	25% 10% 27% 30% 7% 1	760
December	1st to 10th	Night	31% 14% 27% 23% 5%	760
	11th to 20th	Night	25% 14% 29% 25% 5%	760
	21st to end	Night	28% 15% 26% 28% 2	836

Page generated at 2024-11-03 02:11:07. Version ac07

Copyright © 2024 Attilla Danko.