Syracuse
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Syracuse clear sky chart from 2005-11-06 to 2026-06-16.

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% 11% 4 10% 6% 5% 5% 4 5% 7% 28%	138126
	Night	17% 13% 5% 11% 6% 5% 4 3 5% 6% 26%	133876
Transparency	Day	54% 6% 12% 19% 9% 1	141644
	Night	58% 6% 11% 16% 8% 1	138446
Seeing	Day	25% 18% 28% 18% 8% 3	16653
	Night	25% 16% 26% 24% 8% 1	25897

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	14% 19% 8% 23% 7% 4 4 3 3 4 13%	4661
	11th to 20th	Day	11% 19% 9% 16% 11% 7% 5% 4 4 4 10%	4650
	21st to end	Day	14% 15% 6% 16% 11% 9% 6% 4 4 4 12%	5697
February	1st to 10th	Day	15% 17% 5% 16% 9% 7% 6% 3 4 4 12%	1890
	11th to 20th	Day	14% 17% 6% 19% 9% 5% 5% 3 4 5% 14%	1877
	21st to end	Day	17% 18% 5% 15% 8% 4 4 3 4 4 18%	1730
March	1st to 10th	Day	20% 13% 6% 14% 8% 5% 3 2 3 4 22%	4667
	11th to 20th	Day	12% 18% 5% 9% 5% 4 3 3 4 6% 30%	5090
	21st to end	Day	17% 13% 5% 11% 5% 4 4 3 4 5% 29%	5853
April	1st to 10th	Day	20% 12% 5% 9% 5% 4 4 3 4 6% 28%	2520
	11th to 20th	Day	18% 11% 3 7% 5% 4 5% 3 5% 6% 33%	2494
	21st to end	Day	21% 11% 3 7% 5% 4 4 3 5% 6% 31%	2551
May	1st to 10th	Day	27% 9% 3 7% 4 4 4 3 5% 6% 27%	8136
	11th to 20th	Day	17% 9% 3 8% 4 5% 5% 4 6% 7% 33%	8221
	21st to end	Day	22% 7% 3 6% 4 4 4 4 6% 8% 31%	9060
June	1st to 10th	Day	18% 7% 3 7% 5% 4 4 4 6% 8% 34%	2940
	11th to 20th	Day	17% 6% 3 6% 5% 4 5% 5% 7% 9% 34%	2870
	21st to end	Day	15% 6% 2 6% 6% 5% 5% 5% 7% 8% 34%	2800
July	1st to 10th	Day	10% 5% 2 6% 5% 5% 5% 5% 7% 10% 39%	6360
	11th to 20th	Day	9% 5% 2 7% 5% 5% 6% 5% 8% 11% 35%	6360
	21st to end	Day	12% 5% 3 6% 5% 4 5% 4 6% 8% 43%	6926
August	1st to 10th	Day	17% 6% 2 7% 4 4 5% 4 7% 8% 35%	4277
	11th to 20th	Day	14% 7% 3 8% 5% 5% 5% 4 6% 8% 34%	4057
	21st to end	Day	15% 7% 3 6% 5% 5% 4 3 5% 8% 39%	4312
September	1st to 10th	Day	15% 6% 2 5% 4 5% 4 4 6% 8% 42%	2400
	11th to 20th	Day	14% 6% 2 6% 4 4 4 3 5% 7% 44%	2400
	21st to end	Day	17% 7% 3 7% 5% 4 5% 4 7% 6% 35%	2132
October	1st to 10th	Day	18% 7% 2 7% 5% 4 4 4 5% 8% 36%	2000
	11th to 20th	Day	21% 9% 3 6% 5% 4 4 4 6% 7% 31%	2000
	21st to end	Day	24% 13% 3 8% 5% 4 5% 4 5% 6% 24%	2109
November	1st to 10th	Day	15% 13% 4 9% 6% 6% 4 3 5% 6% 31%	1851
	11th to 20th	Day	15% 16% 5% 9% 5% 5% 5% 4 5% 6% 25%	1761
	21st to end	Day	20% 18% 5% 10% 7% 4 4 3 4 6% 18%	1680
December	1st to 10th	Day	18% 20% 8% 17% 7% 5% 4 3 4 4 9%	2680
	11th to 20th	Day	18% 17% 7% 14% 6% 5% 4 3 4 5% 18%	3066
	21st to end	Day	20% 16% 6% 13% 6% 5% 4 4 4 6% 15%	4048
January	1st to 10th	Night	15% 20% 8% 24% 7% 5% 4 3 3 3 8%	8234
	11th to 20th	Night	10% 21% 10% 17% 8% 6% 5% 3 5% 4 12%	8235
	21st to end	Night	13% 14% 5% 16% 10% 9% 5% 4 4 5% 15%	8479
February	1st to 10th	Night	15% 18% 6% 16% 7% 5% 4 3 4 5% 17%	2730
	11th to 20th	Night	14% 15% 6% 17% 9% 6% 6% 3 3 5% 16%	2627
	21st to end	Night	17% 15% 6% 16% 7% 5% 4 3 4 5% 18%	2076
March	1st to 10th	Night	17% 12% 7% 12% 8% 4 4 3 5% 6% 22%	5390
	11th to 20th	Night	17% 17% 5% 8% 4 3 3 3 5% 6% 29%	5089
	21st to end	Night	22% 11% 4 12% 5% 4 4 3 4 4 27%	5320
April	1st to 10th	Night	20% 14% 4 9% 5% 5% 5% 3 5% 6% 26%	2100
	11th to 20th	Night	20% 11% 3 8% 4 5% 4 4 5% 5% 32%	2075
	21st to end	Night	21% 10% 3 6% 4 3 4 3 4 6% 35%	2087
May	1st to 10th	Night	28% 11% 3 7% 5% 4 4 3 5% 5% 25%	4747
	11th to 20th	Night	17% 9% 3 7% 4 4 4 4 6% 8% 34%	4639
	21st to end	Night	23% 7% 2 6% 4 4 4 4 5% 7% 32%	5114
June	1st to 10th	Night	18% 6% 3 7% 5% 4 4 4 6% 7% 36%	1680
	11th to 20th	Night	16% 6% 3 6% 4 4 4 5% 6% 9% 37%	1640
	21st to end	Night	13% 7% 3 7% 5% 4 5% 4 6% 6% 40%	1600
July	1st to 10th	Night	10% 5% 3 8% 6% 6% 5% 4 7% 9% 37%	3600
	11th to 20th	Night	12% 6% 2 7% 5% 4 4 4 6% 9% 42%	3600
	21st to end	Night	10% 5% 2 6% 4 4 4 4 6% 8% 46%	3926
August	1st to 10th	Night	16% 7% 3 6% 4 4 5% 4 6% 8% 39%	2868
	11th to 20th	Night	12% 7% 3 8% 5% 4 4 4 6% 7% 40%	2959
	21st to end	Night	12% 7% 2 6% 4 4 4 4 6% 8% 43%	3586
September	1st to 10th	Night	15% 6% 3 5% 4 4 5% 3 6% 6% 44%	2000
	11th to 20th	Night	15% 5% 2 6% 5% 3 4 3 4 7% 48%	2000
	21st to end	Night	18% 7% 2 6% 3 5% 6% 4 6% 6% 37%	2264
October	1st to 10th	Night	21% 8% 3 6% 5% 5% 5% 4 5% 6% 34%	2400
	11th to 20th	Night	22% 10% 2 7% 4 4 5% 3 5% 6% 33%	2400
	21st to end	Night	26% 12% 4 9% 5% 3 4 4 4 6% 25%	2730
November	1st to 10th	Night	17% 14% 3 8% 5% 4 4 4 4 6% 31%	2667
	11th to 20th	Night	17% 16% 4 8% 6% 4 5% 3 4 6% 27%	2856
	21st to end	Night	17% 19% 5% 9% 5% 5% 4 4 5% 6% 21%	2940
December	1st to 10th	Night	17% 20% 8% 13% 7% 6% 5% 4 4 5% 10%	4720
	11th to 20th	Night	21% 17% 7% 12% 5% 4 4 3 4 4 20%	5348
	21st to end	Night	24% 18% 6% 11% 6% 4 3 2 4 5% 17%	7150

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% 5% 9% 8% 2	4662
	11th to 20th	Day	76% 5% 9% 5% 4 1	4680
	21st to end	Day	75% 4 11% 8% 3	5697
February	1st to 10th	Day	76% 5% 8% 10% 2	1890
	11th to 20th	Day	74% 6% 7% 10% 2	1886
	21st to end	Day	71% 4 9% 12% 4	1730
March	1st to 10th	Day	66% 5% 11% 12% 6% 1	4670
	11th to 20th	Day	55% 5% 18% 12% 9% 1	5090
	21st to end	Day	57% 5% 8% 16% 13% 1	5853
April	1st to 10th	Day	58% 6% 8% 17% 9% 2	2520
	11th to 20th	Day	51% 7% 10% 20% 12% 1	2494
	21st to end	Day	53% 6% 9% 19% 11% 2	2551
May	1st to 10th	Day	57% 6% 10% 17% 9% 1	8147
	11th to 20th	Day	48% 7% 11% 24% 9% 1	8225
	21st to end	Day	50% 6% 13% 21% 9%	9061
June	1st to 10th	Day	47% 8% 10% 20% 13% 1	2940
	11th to 20th	Day	45% 8% 13% 22% 11% 1	2870
	21st to end	Day	45% 9% 14% 20% 11% 1	2800
July	1st to 10th	Day	38% 7% 14% 27% 13%	6290
	11th to 20th	Day	39% 8% 16% 25% 11%	6285
	21st to end	Day	37% 7% 13% 30% 13%	6728
August	1st to 10th	Day	44% 8% 15% 19% 14% 1	4263
	11th to 20th	Day	45% 8% 17% 23% 7% 1	4096
	21st to end	Day	42% 6% 13% 31% 7% 1	4312
September	1st to 10th	Day	39% 9% 12% 28% 11% 1	2400
	11th to 20th	Day	39% 7% 10% 27% 16% 1	2400
	21st to end	Day	47% 7% 11% 23% 10% 1	2132
October	1st to 10th	Day	42% 5% 16% 26% 10% 1	3260
	11th to 20th	Day	47% 5% 15% 20% 12%	3240
	21st to end	Day	47% 7% 15% 21% 8% 1	3386
November	1st to 10th	Day	54% 8% 11% 17% 10% 1	1851
	11th to 20th	Day	60% 6% 11% 15% 7% 2	1761
	21st to end	Day	67% 6% 13% 11% 2	1680
December	1st to 10th	Day	78% 7% 8% 6% 1	2680
	11th to 20th	Day	70% 6% 11% 9% 5%	3066
	21st to end	Day	69% 6% 12% 9% 4	4048
January	1st to 10th	Night	82% 4 8% 5% 1	8234
	11th to 20th	Night	75% 5% 8% 7% 5%	8280
	21st to end	Night	71% 4 10% 8% 7% 1	8479
February	1st to 10th	Night	69% 5% 8% 12% 5%	2730
	11th to 20th	Night	71% 6% 9% 10% 4	2629
	21st to end	Night	69% 5% 11% 9% 6%	2076
March	1st to 10th	Night	63% 6% 11% 13% 6%	5400
	11th to 20th	Night	56% 5% 17% 13% 5% 3	5090
	21st to end	Night	59% 6% 6% 19% 9% 1	5320
April	1st to 10th	Night	59% 7% 10% 15% 7% 2	2100
	11th to 20th	Night	53% 7% 9% 17% 13% 1	2075
	21st to end	Night	51% 5% 10% 18% 13% 3	2087
May	1st to 10th	Night	61% 4 9% 13% 10% 2	4753
	11th to 20th	Night	47% 7% 13% 22% 10% 1	4640
	21st to end	Night	50% 7% 12% 18% 11% 1	5115
June	1st to 10th	Night	46% 7% 12% 21% 14% 1	1680
	11th to 20th	Night	44% 7% 13% 20% 14% 1	1640
	21st to end	Night	43% 7% 11% 25% 13% 1	1600
July	1st to 10th	Night	42% 7% 13% 22% 14% 1	3560
	11th to 20th	Night	39% 7% 14% 24% 15%	3552
	21st to end	Night	35% 6% 11% 30% 17% 1	3809
August	1st to 10th	Night	43% 7% 15% 25% 10% 1	2858
	11th to 20th	Night	42% 7% 17% 24% 9%	2986
	21st to end	Night	37% 7% 14% 32% 10% 1	3586
September	1st to 10th	Night	39% 8% 13% 26% 13% 2	2000
	11th to 20th	Night	38% 5% 12% 28% 16% 1	2000
	21st to end	Night	45% 7% 13% 23% 11% 1	2264
October	1st to 10th	Night	51% 6% 10% 22% 10%	3920
	11th to 20th	Night	50% 6% 13% 17% 13% 1	3899
	21st to end	Night	51% 5% 12% 24% 7% 1	4403
November	1st to 10th	Night	54% 6% 11% 17% 9% 2	2667
	11th to 20th	Night	58% 7% 11% 16% 6% 2	2856
	21st to end	Night	64% 6% 14% 12% 4	2940
December	1st to 10th	Night	76% 6% 10% 7% 1	4720
	11th to 20th	Night	68% 6% 8% 10% 7%	5348
	21st to end	Night	72% 5% 7% 10% 5%	7150

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	35% 25% 27% 10% 3	220
	11th to 20th	Day	35% 29% 28% 7% 1	220
	21st to end	Day	27% 28% 35% 7% 2	347
February	1st to 10th	Day	33% 28% 30% 7% 2	330
	11th to 20th	Day	36% 30% 27% 5%	364
	21st to end	Day	37% 23% 30% 9% 1	446
March	1st to 10th	Day	32% 22% 29% 14% 2	540
	11th to 20th	Day	34% 22% 27% 12% 3	540
	21st to end	Day	35% 22% 27% 11% 4 1	594
April	1st to 10th	Day	36% 23% 25% 12% 4	540
	11th to 20th	Day	31% 25% 23% 12% 6% 3	532
	21st to end	Day	33% 17% 28% 15% 5% 2	540
May	1st to 10th	Day	29% 20% 30% 13% 7% 1	543
	11th to 20th	Day	21% 16% 32% 21% 8% 2	567
	21st to end	Day	22% 12% 32% 22% 10% 3	617
June	1st to 10th	Day	22% 16% 26% 24% 10% 2	570
	11th to 20th	Day	17% 15% 31% 24% 11% 2	550
	21st to end	Day	18% 18% 32% 24% 7% 2	530
July	1st to 10th	Day	12% 9% 32% 28% 16% 4	525
	11th to 20th	Day	13% 9% 28% 31% 17% 3	524
	21st to end	Day	14% 8% 36% 26% 13% 3	576
August	1st to 10th	Day	12% 9% 28% 27% 17% 7%	526
	11th to 20th	Day	15% 11% 25% 27% 14% 7%	519
	21st to end	Day	13% 13% 32% 21% 14% 7%	583
September	1st to 10th	Day	17% 13% 22% 25% 15% 8%	530
	11th to 20th	Day	12% 11% 23% 24% 19% 12%	530
	21st to end	Day	18% 14% 28% 24% 13% 4	530
October	1st to 10th	Day	22% 12% 27% 18% 15% 5%	530
	11th to 20th	Day	28% 20% 25% 18% 7% 2	530
	21st to end	Day	33% 16% 30% 17% 4	532
November	1st to 10th	Day	30% 22% 23% 18% 7%	425
	11th to 20th	Day	32% 25% 24% 15% 3 1	301
	21st to end	Day	40% 19% 34% 8%	220
December	1st to 10th	Day	36% 22% 30% 8% 3	220
	11th to 20th	Day	31% 30% 28% 9% 1	220
	21st to end	Day	34% 23% 30% 12%	242
January	1st to 10th	Night	31% 26% 29% 12% 2	840
	11th to 20th	Night	29% 25% 29% 14% 3	840
	21st to end	Night	22% 25% 33% 17% 3	924
February	1st to 10th	Night	29% 22% 30% 17% 1	840
	11th to 20th	Night	27% 25% 30% 15% 2	823
	21st to end	Night	29% 23% 30% 15% 2	692
March	1st to 10th	Night	28% 21% 29% 19% 2	840
	11th to 20th	Night	28% 23% 27% 20% 2	840
	21st to end	Night	29% 19% 27% 18% 6%	924
April	1st to 10th	Night	28% 19% 29% 21% 2	840
	11th to 20th	Night	28% 19% 25% 21% 6% 1	831
	21st to end	Night	27% 14% 26% 27% 6%	827
May	1st to 10th	Night	28% 12% 22% 29% 8% 1	455
	11th to 20th	Night	16% 10% 33% 34% 7% 1	414
	21st to end	Night	14% 10% 28% 35% 13%	455
June	1st to 10th	Night	21% 7% 20% 39% 12% 1	420
	11th to 20th	Night	17% 8% 23% 36% 15%	410
	21st to end	Night	16% 7% 26% 42% 9% 1	400
July	1st to 10th	Night	10% 5% 19% 47% 17% 2	390
	11th to 20th	Night	12% 4 19% 45% 18% 2	388
	21st to end	Night	13% 6% 22% 45% 12% 1	438
August	1st to 10th	Night	13% 5% 21% 39% 21% 1	563
	11th to 20th	Night	14% 6% 21% 32% 25% 2	639
	21st to end	Night	16% 6% 21% 35% 21% 1	880
September	1st to 10th	Night	17% 7% 24% 31% 19% 2	800
	11th to 20th	Night	16% 7% 18% 30% 24% 4	800
	21st to end	Night	19% 12% 20% 30% 17% 2	800
October	1st to 10th	Night	27% 11% 22% 22% 17% 1	800
	11th to 20th	Night	27% 14% 28% 25% 6% 1	800
	21st to end	Night	34% 16% 26% 21% 3	880
November	1st to 10th	Night	28% 17% 28% 20% 7%	820
	11th to 20th	Night	30% 21% 26% 17% 5% 1	840
	21st to end	Night	30% 23% 27% 16% 4	840
December	1st to 10th	Night	33% 24% 27% 14% 2	840
	11th to 20th	Night	33% 23% 27% 14% 3	840
	21st to end	Night	34% 23% 27% 14% 2	924

Page generated at 2026-06-13 02:31:39. Version ac07

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