New Paltz
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the New Paltz clear sky chart from 2005-11-06 to 2025-07-06.

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	17% 7% 2 6% 5% 4 5% 4 6% 7% 38%	119872
	Night	18% 7% 2 6% 4 4 4 3 5% 6% 40%	118887
Transparency	Day	43% 7% 13% 21% 14% 2	123418
	Night	43% 6% 13% 21% 15% 2	123489
Seeing	Day	21% 14% 28% 24% 10% 3	15714
	Night	20% 10% 31% 29% 9% 1	24843

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	11% 8% 4 8% 5% 5% 5% 4 5% 6% 40%	3597
	11th to 20th	Day	13% 9% 4 9% 6% 5% 5% 4 6% 6% 35%	3570
	21st to end	Day	16% 9% 3 6% 5% 5% 5% 4 5% 5% 38%	4218
February	1st to 10th	Day	14% 11% 3 8% 5% 5% 4 4 5% 6% 34%	1800
	11th to 20th	Day	13% 8% 2 8% 5% 5% 5% 4 5% 6% 39%	1930
	21st to end	Day	18% 9% 3 6% 4 4 5% 4 5% 6% 37%	1650
March	1st to 10th	Day	22% 7% 2 6% 4 4 4 3 4 5% 39%	4476
	11th to 20th	Day	13% 7% 3 6% 4 4 4 3 5% 6% 44%	4768
	21st to end	Day	19% 7% 2 7% 5% 4 5% 3 5% 5% 38%	5923
April	1st to 10th	Day	18% 9% 3 7% 5% 3 4 3 5% 6% 36%	2400
	11th to 20th	Day	16% 8% 2 6% 5% 4 4 3 5% 6% 40%	2374
	21st to end	Day	20% 6% 2 6% 4 4 4 3 5% 6% 40%	2449
May	1st to 10th	Day	30% 7% 2 5% 4 3 4 4 6% 6% 28%	5950
	11th to 20th	Day	20% 7% 2 6% 4 4 4 3 6% 7% 36%	6318
	21st to end	Day	21% 7% 2 5% 4 4 5% 4 6% 9% 34%	6949
June	1st to 10th	Day	16% 5% 2 6% 5% 5% 5% 4 7% 9% 36%	2800
	11th to 20th	Day	15% 5% 2 7% 5% 5% 4 4 8% 9% 36%	2800
	21st to end	Day	13% 5% 2 6% 5% 5% 5% 5% 6% 10% 38%	2800
July	1st to 10th	Day	10% 6% 3 7% 5% 5% 6% 4 7% 9% 37%	4510
	11th to 20th	Day	10% 5% 2 6% 5% 5% 5% 5% 8% 11% 38%	4440
	21st to end	Day	13% 8% 3 8% 6% 5% 5% 4 6% 7% 35%	4814
August	1st to 10th	Day	20% 6% 3 6% 5% 5% 5% 4 6% 8% 33%	4282
	11th to 20th	Day	13% 6% 2 6% 4 4 4 5% 6% 9% 41%	3730
	21st to end	Day	12% 5% 2 6% 4 5% 4 4 6% 10% 43%	4180
September	1st to 10th	Day	13% 6% 2 6% 5% 4 5% 3 5% 7% 43%	2280
	11th to 20th	Day	14% 4 2 4 4 4 4 3 5% 6% 50%	2202
	21st to end	Day	18% 6% 1 5% 3 5% 4 4 5% 6% 42%	2090
October	1st to 10th	Day	20% 5% 2 6% 4 4 4 3 4 6% 42%	1973
	11th to 20th	Day	14% 6% 2 6% 4 4 5% 3 5% 7% 44%	1900
	21st to end	Day	22% 6% 2 6% 4 4 5% 3 5% 6% 37%	1922
November	1st to 10th	Day	12% 8% 2 5% 4 3 3 2 4 6% 50%	1761
	11th to 20th	Day	17% 7% 1 5% 4 4 4 3 5% 6% 43%	1800
	21st to end	Day	18% 8% 2 6% 4 4 4 3 5% 7% 39%	1670
December	1st to 10th	Day	16% 7% 3 7% 5% 5% 6% 4 5% 7% 38%	2600
	11th to 20th	Day	23% 7% 2 4 3 3 4 4 4 6% 40%	2986
	21st to end	Day	18% 9% 3 7% 5% 5% 4 4 5% 7% 33%	3960
January	1st to 10th	Night	14% 6% 2 8% 5% 5% 4 3 5% 6% 42%	6349
	11th to 20th	Night	13% 8% 3 9% 6% 5% 4 4 6% 6% 37%	6315
	21st to end	Night	17% 9% 3 6% 5% 4 4 4 5% 6% 38%	6720
February	1st to 10th	Night	15% 9% 3 7% 4 5% 4 4 5% 5% 38%	2600
	11th to 20th	Night	14% 8% 3 7% 6% 4 5% 4 6% 6% 39%	2354
	21st to end	Night	16% 9% 2 7% 4 4 4 4 4 5% 41%	1980
March	1st to 10th	Night	20% 7% 3 5% 3 3 3 3 5% 6% 40%	5364
	11th to 20th	Night	15% 9% 3 6% 4 4 4 3 5% 6% 41%	5174
	21st to end	Night	18% 10% 3 6% 5% 4 4 3 4 5% 39%	5008
April	1st to 10th	Night	19% 9% 2 8% 5% 5% 4 3 6% 6% 33%	2000
	11th to 20th	Night	19% 7% 2 6% 5% 4 4 3 5% 7% 38%	1975
	21st to end	Night	21% 7% 3 5% 4 4 3 3 4 5% 42%	1950
May	1st to 10th	Night	33% 7% 2 5% 3 3 3 3 5% 6% 29%	4020
	11th to 20th	Night	22% 7% 2 7% 5% 4 3 3 5% 7% 34%	3575
	21st to end	Night	20% 8% 2 7% 4 4 4 3 6% 7% 35%	3926
June	1st to 10th	Night	16% 5% 2 6% 4 4 4 4 5% 8% 41%	1600
	11th to 20th	Night	15% 6% 2 5% 4 4 4 5% 6% 10% 41%	1600
	21st to end	Night	13% 4 2 5% 3 5% 4 4 7% 11% 43%	1600
July	1st to 10th	Night	11% 5% 2 6% 4 5% 6% 5% 7% 9% 40%	2560
	11th to 20th	Night	12% 5% 3 6% 5% 5% 5% 4 7% 9% 39%	2520
	21st to end	Night	15% 8% 2 6% 5% 5% 4 3 5% 6% 40%	2739
August	1st to 10th	Night	21% 5% 3 7% 5% 4 5% 4 6% 7% 34%	2619
	11th to 20th	Night	14% 7% 3 7% 5% 5% 4 4 5% 6% 42%	3092
	21st to end	Night	13% 4 2 5% 4 3 4 4 4 6% 51%	3476
September	1st to 10th	Night	14% 6% 3 5% 4 4 4 3 4 7% 46%	1900
	11th to 20th	Night	13% 4 2 4 4 3 3 2 4 7% 54%	1977
	21st to end	Night	17% 6% 2 4 4 3 3 3 5% 7% 45%	2090
October	1st to 10th	Night	20% 7% 3 5% 4 3 3 3 4 5% 41%	2204
	11th to 20th	Night	16% 6% 2 5% 3 4 3 3 4 5% 48%	2280
	21st to end	Night	24% 6% 2 6% 4 3 3 3 4 6% 39%	2674
November	1st to 10th	Night	13% 6% 2 6% 4 4 4 4 5% 6% 47%	2537
	11th to 20th	Night	18% 7% 2 5% 4 3 4 4 4 5% 43%	2600
	21st to end	Night	16% 6% 2 5% 5% 3 4 3 6% 6% 43%	2725
December	1st to 10th	Night	16% 9% 2 6% 4 4 4 3 5% 5% 43%	4580
	11th to 20th	Night	26% 8% 2 5% 3 3 3 3 5% 5% 37%	5208
	21st to end	Night	20% 10% 3 7% 4 4 3 3 5% 6% 35%	6996

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	42% 6% 12% 25% 12% 3	3598
	11th to 20th	Day	46% 7% 10% 19% 12% 5%	3600
	21st to end	Day	46% 6% 10% 24% 14% 1	4218
February	1st to 10th	Day	49% 6% 13% 18% 13% 1	1800
	11th to 20th	Day	45% 7% 11% 21% 14% 3	1939
	21st to end	Day	47% 5% 12% 21% 12% 2	1650
March	1st to 10th	Day	47% 5% 11% 18% 11% 8%	4479
	11th to 20th	Day	38% 7% 15% 27% 8% 4	4768
	21st to end	Day	47% 6% 7% 13% 21% 6%	5923
April	1st to 10th	Day	48% 6% 10% 19% 13% 4	2400
	11th to 20th	Day	44% 6% 11% 21% 16% 3	2374
	21st to end	Day	45% 6% 10% 20% 16% 4	2449
May	1st to 10th	Day	55% 7% 13% 15% 10% 1	5961
	11th to 20th	Day	47% 8% 12% 20% 12% 1	6322
	21st to end	Day	44% 8% 13% 22% 11% 1	6949
June	1st to 10th	Day	42% 9% 16% 20% 13% 1	2800
	11th to 20th	Day	42% 8% 16% 22% 10% 1	2800
	21st to end	Day	41% 9% 13% 24% 13% 1	2800
July	1st to 10th	Day	42% 9% 13% 20% 16% 1	4440
	11th to 20th	Day	37% 9% 17% 23% 13% 1	4365
	21st to end	Day	46% 7% 13% 17% 15% 1	4661
August	1st to 10th	Day	49% 8% 15% 19% 9% 1	4268
	11th to 20th	Day	37% 8% 18% 28% 9%	3766
	21st to end	Day	36% 7% 14% 29% 14% 1	4180
September	1st to 10th	Day	40% 7% 12% 22% 17% 1	2280
	11th to 20th	Day	34% 6% 11% 25% 23% 2	2202
	21st to end	Day	40% 8% 12% 21% 17% 3	2090
October	1st to 10th	Day	40% 7% 9% 20% 23% 3	3272
	11th to 20th	Day	32% 5% 9% 27% 24% 2	3140
	21st to end	Day	32% 5% 16% 25% 19% 4	3147
November	1st to 10th	Day	36% 5% 14% 25% 17% 2	1761
	11th to 20th	Day	41% 6% 11% 22% 18% 2	1800
	21st to end	Day	44% 5% 15% 25% 9% 2	1670
December	1st to 10th	Day	46% 6% 15% 25% 8% 1	2600
	11th to 20th	Day	45% 5% 14% 22% 13% 2	2986
	21st to end	Day	49% 7% 10% 19% 13% 1	3960
January	1st to 10th	Night	43% 5% 11% 21% 17% 2	6349
	11th to 20th	Night	45% 6% 16% 17% 12% 5%	6360
	21st to end	Night	46% 5% 12% 16% 16% 4	6720
February	1st to 10th	Night	47% 6% 14% 21% 11% 1	2600
	11th to 20th	Night	45% 6% 12% 17% 16% 4	2356
	21st to end	Night	45% 6% 10% 22% 13% 4	1980
March	1st to 10th	Night	44% 6% 12% 18% 14% 6%	5374
	11th to 20th	Night	41% 7% 16% 23% 10% 3	5175
	21st to end	Night	48% 5% 7% 14% 23% 4	5008
April	1st to 10th	Night	49% 7% 10% 18% 13% 2	2000
	11th to 20th	Night	45% 7% 11% 17% 19% 1	1975
	21st to end	Night	44% 7% 9% 20% 16% 3	1950
May	1st to 10th	Night	56% 6% 13% 14% 10% 1	4026
	11th to 20th	Night	50% 8% 13% 15% 14% 1	3576
	21st to end	Night	47% 7% 13% 22% 10% 1	3927
June	1st to 10th	Night	41% 7% 11% 22% 17% 2	1600
	11th to 20th	Night	38% 10% 17% 25% 10% 1	1600
	21st to end	Night	34% 10% 15% 25% 14% 2	1600
July	1st to 10th	Night	38% 9% 16% 19% 15% 2	2520
	11th to 20th	Night	40% 8% 15% 24% 13% 1	2472
	21st to end	Night	43% 8% 13% 17% 16% 2	2651
August	1st to 10th	Night	49% 9% 15% 18% 9% 1	2609
	11th to 20th	Night	41% 8% 15% 26% 10%	3122
	21st to end	Night	32% 7% 12% 33% 15% 1	3476
September	1st to 10th	Night	39% 6% 12% 25% 17% 1	1900
	11th to 20th	Night	32% 5% 11% 26% 25% 1	1977
	21st to end	Night	38% 6% 11% 22% 21% 1	2090
October	1st to 10th	Night	43% 6% 11% 21% 18% 1	3672
	11th to 20th	Night	29% 5% 9% 30% 26% 2	3779
	21st to end	Night	34% 5% 14% 30% 16% 1	4399
November	1st to 10th	Night	38% 6% 11% 23% 20% 3	2537
	11th to 20th	Night	43% 4 12% 21% 17% 4	2600
	21st to end	Night	40% 6% 16% 27% 10% 1	2725
December	1st to 10th	Night	43% 5% 14% 29% 8% 1	4580
	11th to 20th	Night	49% 6% 14% 16% 15% 2	5208
	21st to end	Night	49% 6% 11% 17% 14% 3	6996

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% 21% 28% 17% 8%	200
	11th to 20th	Day	26% 23% 32% 16% 3 1	200
	21st to end	Day	22% 19% 38% 16% 4 1	277
February	1st to 10th	Day	29% 21% 35% 12% 2	300
	11th to 20th	Day	24% 22% 36% 17% 1	478
	21st to end	Day	26% 20% 35% 16% 3	414
March	1st to 10th	Day	26% 18% 32% 19% 4	500
	11th to 20th	Day	22% 24% 31% 17% 4 1	500
	21st to end	Day	29% 18% 29% 18% 4 3	550
April	1st to 10th	Day	29% 20% 27% 16% 6% 2	500
	11th to 20th	Day	25% 24% 28% 14% 7% 2	492
	21st to end	Day	27% 16% 29% 19% 6% 2	500
May	1st to 10th	Day	32% 16% 25% 19% 7% 2	503
	11th to 20th	Day	18% 14% 35% 22% 9% 2	527
	21st to end	Day	20% 11% 25% 28% 12% 4	573
June	1st to 10th	Day	19% 12% 27% 26% 13% 3	530
	11th to 20th	Day	15% 13% 28% 28% 13% 3	530
	21st to end	Day	15% 11% 28% 28% 14% 4	530
July	1st to 10th	Day	14% 6% 24% 35% 17% 5%	505
	11th to 20th	Day	12% 6% 24% 35% 18% 5%	484
	21st to end	Day	13% 8% 26% 34% 16% 4	532
August	1st to 10th	Day	14% 6% 22% 35% 17% 7%	486
	11th to 20th	Day	14% 5% 25% 29% 18% 8%	479
	21st to end	Day	10% 9% 25% 31% 17% 9%	539
September	1st to 10th	Day	19% 10% 20% 24% 19% 8%	490
	11th to 20th	Day	14% 7% 28% 21% 17% 13%	490
	21st to end	Day	20% 9% 25% 27% 13% 6%	490
October	1st to 10th	Day	26% 10% 20% 23% 16% 6%	490
	11th to 20th	Day	17% 12% 31% 26% 11% 3	490
	21st to end	Day	24% 14% 29% 22% 10% 1	450
November	1st to 10th	Day	17% 14% 28% 29% 10% 3	395
	11th to 20th	Day	23% 17% 29% 26% 6% 1	400
	21st to end	Day	21% 15% 31% 26% 6% 1	270
December	1st to 10th	Day	21% 23% 35% 15% 8% 1	200
	11th to 20th	Day	29% 19% 33% 17% 3	200
	21st to end	Day	20% 15% 38% 21% 5% 1	220
January	1st to 10th	Night	19% 15% 37% 26% 3	800
	11th to 20th	Night	22% 13% 36% 26% 3	800
	21st to end	Night	17% 13% 42% 25% 3	880
February	1st to 10th	Night	21% 15% 38% 25% 2	800
	11th to 20th	Night	21% 15% 42% 21% 1	783
	21st to end	Night	23% 14% 39% 21% 3	660
March	1st to 10th	Night	22% 17% 35% 23% 3	800
	11th to 20th	Night	21% 16% 36% 22% 5%	800
	21st to end	Night	22% 16% 36% 20% 6%	880
April	1st to 10th	Night	25% 16% 34% 22% 4	800
	11th to 20th	Night	21% 14% 35% 24% 6%	791
	21st to end	Night	23% 15% 30% 26% 6%	750
May	1st to 10th	Night	26% 13% 31% 24% 6%	592
	11th to 20th	Night	19% 7% 35% 33% 5%	394
	21st to end	Night	16% 7% 23% 41% 13% 1	433
June	1st to 10th	Night	17% 5% 27% 37% 14%	400
	11th to 20th	Night	16% 5% 24% 38% 16% 1	400
	21st to end	Night	14% 4 24% 42% 17%	400
July	1st to 10th	Night	14% 2 18% 45% 21% 1	380
	11th to 20th	Night	12% 4 20% 45% 18% 1	368
	21st to end	Night	12% 4 20% 46% 18% 1	416
August	1st to 10th	Night	14% 2 14% 48% 20% 2	439
	11th to 20th	Night	13% 4 16% 41% 23% 3	745
	21st to end	Night	15% 3 17% 38% 24% 3	836
September	1st to 10th	Night	17% 3 23% 36% 18% 2	760
	11th to 20th	Night	15% 4 22% 31% 23% 5%	760
	21st to end	Night	18% 6% 24% 34% 16% 2	760
October	1st to 10th	Night	24% 6% 24% 29% 15% 1	760
	11th to 20th	Night	18% 8% 28% 36% 9% 1	760
	21st to end	Night	27% 9% 30% 27% 7%	836
November	1st to 10th	Night	15% 9% 33% 31% 10% 1	780
	11th to 20th	Night	23% 11% 32% 26% 7% 1	800
	21st to end	Night	19% 11% 35% 28% 6% 1	800
December	1st to 10th	Night	24% 13% 34% 23% 6%	800
	11th to 20th	Night	25% 11% 33% 27% 4	800
	21st to end	Night	24% 11% 38% 24% 3	880

Page generated at 2025-07-03 01:30:12. Version ac07

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