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 2025-02-21.

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% 11% 4 10% 6% 5% 4 4 5% 7% 29%	108730
	Night	17% 13% 5% 11% 6% 4 4 3 5% 6% 26%	109841
Transparency	Day	53% 7% 12% 18% 9% 1	112295
	Night	58% 6% 11% 16% 8% 1	114440
Seeing	Day	25% 17% 29% 18% 8% 3	14916
	Night	25% 17% 26% 23% 8% 1	24272

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	12% 19% 8% 23% 6% 4 4 3 4 4 14%	3597
	11th to 20th	Day	13% 21% 9% 16% 10% 6% 4 3 3 4 11%	3570
	21st to end	Day	16% 16% 6% 15% 8% 5% 5% 4 4 5% 15%	4397
February	1st to 10th	Day	15% 18% 5% 15% 10% 7% 5% 3 4 4 13%	1800
	11th to 20th	Day	14% 16% 6% 19% 10% 5% 5% 3 4 4 14%	1785
	21st to end	Day	18% 17% 5% 15% 8% 4 4 3 4 4 18%	1570
March	1st to 10th	Day	23% 14% 5% 10% 5% 4 3 2 3 5% 25%	3177
	11th to 20th	Day	11% 21% 5% 10% 5% 5% 3 3 4 6% 26%	3480
	21st to end	Day	17% 13% 4 10% 4 3 3 3 4 6% 32%	3993
April	1st to 10th	Day	20% 13% 4 9% 4 4 4 3 4 6% 29%	2280
	11th to 20th	Day	18% 10% 3 7% 5% 4 4 3 5% 7% 34%	2254
	21st to end	Day	21% 12% 3 6% 5% 4 3 3 5% 6% 32%	2308
May	1st to 10th	Day	23% 10% 2 7% 4 4 4 3 5% 6% 32%	4380
	11th to 20th	Day	16% 8% 3 9% 6% 5% 5% 4 6% 8% 30%	4398
	21st to end	Day	13% 6% 2 6% 4 5% 4 4 7% 9% 41%	4837
June	1st to 10th	Day	18% 8% 2 8% 5% 4 5% 4 6% 8% 32%	2660
	11th to 20th	Day	16% 6% 2 6% 5% 5% 5% 5% 7% 9% 35%	2660
	21st to end	Day	15% 7% 2 6% 6% 5% 5% 5% 7% 8% 33%	2660
July	1st to 10th	Day	11% 5% 2 6% 5% 5% 5% 5% 8% 11% 37%	4440
	11th to 20th	Day	10% 5% 2 7% 5% 5% 6% 5% 9% 11% 35%	4440
	21st to end	Day	10% 6% 3 7% 6% 5% 6% 5% 7% 9% 37%	4814
August	1st to 10th	Day	17% 6% 3 7% 4 4 5% 4 7% 8% 34%	4146
	11th to 20th	Day	14% 7% 3 8% 5% 5% 5% 4 6% 8% 33%	3930
	21st to end	Day	16% 7% 3 6% 5% 5% 4 3 5% 8% 39%	4180
September	1st to 10th	Day	15% 6% 2 5% 4 5% 4 4 6% 8% 41%	2280
	11th to 20th	Day	14% 6% 2 6% 4 4 4 3 5% 7% 43%	2280
	21st to end	Day	17% 7% 3 7% 5% 4 4 4 7% 6% 35%	2026
October	1st to 10th	Day	19% 8% 2 8% 5% 4 4 4 5% 8% 33%	1900
	11th to 20th	Day	20% 9% 3 6% 5% 4 4 4 6% 7% 31%	1900
	21st to end	Day	24% 13% 3 7% 5% 4 5% 3 5% 6% 23%	2004
November	1st to 10th	Day	14% 12% 4 9% 6% 6% 4 3 5% 7% 31%	1761
	11th to 20th	Day	15% 15% 5% 9% 5% 5% 5% 4 5% 6% 25%	1677
	21st to end	Day	20% 17% 5% 10% 7% 5% 4 3 4 7% 19%	1600
December	1st to 10th	Day	18% 20% 8% 18% 8% 5% 4 2 4 4 9%	2600
	11th to 20th	Day	18% 17% 7% 13% 6% 5% 4 3 4 5% 18%	2986
	21st to end	Day	20% 16% 6% 12% 6% 5% 4 4 4 6% 15%	3960
January	1st to 10th	Night	14% 19% 8% 25% 7% 5% 4 3 3 3 8%	6349
	11th to 20th	Night	10% 19% 10% 18% 8% 5% 5% 3 4 4 13%	6315
	21st to end	Night	15% 17% 6% 17% 8% 6% 4 3 4 5% 15%	6554
February	1st to 10th	Night	16% 18% 6% 15% 7% 5% 4 3 4 5% 17%	2600
	11th to 20th	Night	14% 15% 6% 17% 9% 6% 6% 3 3 5% 16%	2499
	21st to end	Night	18% 14% 6% 15% 7% 4 4 3 4 5% 19%	1885
March	1st to 10th	Night	20% 13% 5% 10% 6% 4 4 3 5% 6% 26%	3660
	11th to 20th	Night	15% 22% 6% 9% 5% 4 4 3 4 5% 22%	3479
	21st to end	Night	20% 12% 4 11% 5% 4 4 3 3 4 30%	3638
April	1st to 10th	Night	19% 14% 4 8% 5% 5% 5% 3 5% 6% 27%	1900
	11th to 20th	Night	19% 11% 3 8% 4 5% 4 4 5% 5% 33%	1875
	21st to end	Night	21% 11% 3 6% 4 3 4 3 4 6% 34%	1889
May	1st to 10th	Night	24% 10% 3 8% 5% 4 4 3 5% 6% 29%	2559
	11th to 20th	Night	16% 9% 3 7% 5% 4 5% 4 6% 7% 34%	2495
	21st to end	Night	13% 6% 2 6% 4 4 5% 4 7% 8% 40%	2738
June	1st to 10th	Night	18% 6% 3 7% 5% 4 4 4 6% 7% 36%	1520
	11th to 20th	Night	16% 6% 3 6% 4 4 4 5% 6% 9% 38%	1520
	21st to end	Night	13% 7% 3 7% 5% 4 5% 4 6% 7% 40%	1520
July	1st to 10th	Night	11% 5% 3 8% 6% 5% 5% 4 8% 7% 38%	2520
	11th to 20th	Night	11% 5% 2 6% 4 5% 4 4 7% 9% 43%	2520
	21st to end	Night	12% 6% 2 6% 5% 4 5% 4 6% 8% 42%	2739
August	1st to 10th	Night	16% 7% 3 6% 4 4 5% 4 6% 7% 38%	2779
	11th to 20th	Night	12% 7% 3 8% 5% 4 4 4 6% 7% 40%	2867
	21st to end	Night	12% 6% 2 6% 4 4 4 4 6% 9% 43%	3476
September	1st to 10th	Night	15% 6% 2 5% 4 4 5% 3 6% 6% 43%	1900
	11th to 20th	Night	16% 6% 1 6% 5% 3 4 3 4 6% 47%	1900
	21st to end	Night	18% 7% 2 6% 4 5% 6% 4 7% 7% 37%	2151
October	1st to 10th	Night	21% 8% 3 7% 5% 5% 5% 4 5% 6% 32%	2280
	11th to 20th	Night	22% 10% 3 6% 4 4 5% 3 5% 6% 32%	2280
	21st to end	Night	27% 12% 4 9% 4 3 3 4 4 6% 24%	2593
November	1st to 10th	Night	17% 14% 3 8% 5% 4 4 4 4 6% 32%	2537
	11th to 20th	Night	18% 15% 4 8% 6% 4 5% 3 5% 6% 28%	2720
	21st to end	Night	17% 19% 5% 9% 5% 5% 4 4 5% 6% 22%	2800
December	1st to 10th	Night	17% 20% 8% 13% 7% 6% 6% 4 4 5% 10%	4580
	11th to 20th	Night	21% 17% 7% 11% 5% 4 4 3 4 4 20%	5208
	21st to end	Night	24% 18% 6% 11% 7% 4 3 2 4 5% 17%	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	74% 5% 9% 10% 2	3598
	11th to 20th	Day	77% 6% 8% 5% 4 1	3600
	21st to end	Day	72% 4 12% 9% 4	4397
February	1st to 10th	Day	75% 6% 8% 10% 2	1800
	11th to 20th	Day	74% 6% 7% 11% 3	1794
	21st to end	Day	71% 4 9% 12% 4	1570
March	1st to 10th	Day	63% 7% 9% 15% 6%	3180
	11th to 20th	Day	59% 6% 16% 10% 9% 1	3480
	21st to end	Day	54% 6% 8% 19% 12% 1	3993
April	1st to 10th	Day	57% 6% 8% 18% 9% 2	2280
	11th to 20th	Day	50% 7% 10% 20% 12% 1	2254
	21st to end	Day	53% 6% 9% 18% 11% 2	2308
May	1st to 10th	Day	53% 6% 10% 18% 11% 1	4394
	11th to 20th	Day	50% 9% 12% 21% 7% 1	4402
	21st to end	Day	39% 9% 14% 24% 13% 1	4837
June	1st to 10th	Day	49% 9% 10% 19% 12% 1	2660
	11th to 20th	Day	44% 8% 13% 22% 11% 1	2660
	21st to end	Day	45% 9% 14% 20% 10% 1	2660
July	1st to 10th	Day	39% 7% 15% 26% 12% 1	4370
	11th to 20th	Day	37% 9% 16% 27% 10%	4365
	21st to end	Day	40% 9% 16% 24% 11%	4661
August	1st to 10th	Day	45% 8% 15% 19% 13% 1	4132
	11th to 20th	Day	46% 8% 17% 22% 7%	3969
	21st to end	Day	43% 6% 13% 31% 7% 1	4180
September	1st to 10th	Day	40% 9% 12% 27% 11% 1	2280
	11th to 20th	Day	40% 7% 11% 25% 16% 1	2280
	21st to end	Day	47% 7% 11% 24% 10% 1	2026
October	1st to 10th	Day	43% 6% 16% 26% 9%	3160
	11th to 20th	Day	47% 5% 15% 21% 12%	3140
	21st to end	Day	47% 7% 16% 22% 8% 1	3281
November	1st to 10th	Day	53% 8% 11% 17% 10% 1	1761
	11th to 20th	Day	59% 6% 11% 15% 7% 2	1677
	21st to end	Day	66% 6% 14% 12% 2	1600
December	1st to 10th	Day	78% 7% 8% 6% 1	2600
	11th to 20th	Day	69% 6% 11% 8% 5%	2986
	21st to end	Day	69% 6% 13% 9% 4	3960
January	1st to 10th	Night	82% 4 8% 5% 1	6349
	11th to 20th	Night	74% 6% 9% 7% 4	6360
	21st to end	Night	71% 4 10% 7% 8% 1	6554
February	1st to 10th	Night	70% 6% 8% 11% 5%	2600
	11th to 20th	Night	71% 6% 8% 10% 4	2501
	21st to end	Night	67% 6% 11% 10% 6%	1885
March	1st to 10th	Night	58% 7% 12% 16% 7%	3670
	11th to 20th	Night	63% 6% 13% 13% 5%	3480
	21st to end	Night	56% 7% 6% 20% 10% 2	3638
April	1st to 10th	Night	57% 7% 10% 16% 7% 2	1900
	11th to 20th	Night	53% 7% 9% 17% 14% 1	1875
	21st to end	Night	51% 5% 11% 17% 13% 3	1889
May	1st to 10th	Night	55% 5% 12% 15% 9% 4	2565
	11th to 20th	Night	47% 9% 15% 20% 8% 1	2496
	21st to end	Night	38% 10% 14% 19% 17% 2	2739
June	1st to 10th	Night	46% 7% 12% 21% 13% 1	1520
	11th to 20th	Night	43% 7% 13% 21% 14% 2	1520
	21st to end	Night	43% 7% 11% 26% 13% 1	1520
July	1st to 10th	Night	42% 8% 12% 22% 15% 1	2480
	11th to 20th	Night	37% 8% 15% 27% 12% 1	2472
	21st to end	Night	39% 7% 11% 26% 15% 1	2651
August	1st to 10th	Night	43% 8% 15% 25% 9%	2769
	11th to 20th	Night	43% 8% 17% 24% 9%	2894
	21st to end	Night	36% 7% 14% 32% 10% 1	3476
September	1st to 10th	Night	40% 8% 13% 25% 13% 2	1900
	11th to 20th	Night	38% 5% 12% 28% 16% 1	1900
	21st to end	Night	45% 7% 13% 23% 11% 1	2151
October	1st to 10th	Night	52% 6% 10% 22% 9%	3800
	11th to 20th	Night	50% 6% 13% 17% 13% 1	3779
	21st to end	Night	51% 5% 12% 25% 6% 1	4266
November	1st to 10th	Night	54% 6% 11% 17% 10% 2	2537
	11th to 20th	Night	57% 7% 12% 16% 6% 2	2720
	21st to end	Night	64% 6% 14% 13% 4	2800
December	1st to 10th	Night	76% 6% 10% 6% 1	4580
	11th to 20th	Night	68% 6% 8% 10% 8%	5208
	21st to end	Night	71% 6% 7% 10% 5%	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	34% 25% 28% 10% 4	200
	11th to 20th	Day	36% 28% 28% 8% 1 1	200
	21st to end	Day	27% 27% 36% 7% 2	315
February	1st to 10th	Day	35% 29% 30% 5%	300
	11th to 20th	Day	36% 32% 28% 5%	332
	21st to end	Day	38% 22% 28% 10% 1	382
March	1st to 10th	Day	33% 22% 28% 14% 3	460
	11th to 20th	Day	32% 23% 29% 13% 3	460
	21st to end	Day	35% 21% 27% 12% 4 1	506
April	1st to 10th	Day	34% 22% 27% 13% 5%	460
	11th to 20th	Day	31% 25% 22% 12% 7% 3	452
	21st to end	Day	34% 17% 27% 15% 5% 2	460
May	1st to 10th	Day	27% 19% 30% 15% 8% 2	463
	11th to 20th	Day	21% 14% 32% 22% 8% 2	487
	21st to end	Day	19% 12% 31% 23% 11% 3	529
June	1st to 10th	Day	23% 17% 27% 22% 9% 2	490
	11th to 20th	Day	17% 13% 31% 25% 12% 2	490
	21st to end	Day	17% 19% 32% 23% 7% 2	490
July	1st to 10th	Day	12% 9% 31% 29% 16% 4	485
	11th to 20th	Day	13% 8% 28% 31% 16% 3	484
	21st to end	Day	13% 8% 37% 26% 13% 3	532
August	1st to 10th	Day	13% 10% 29% 27% 15% 7%	486
	11th to 20th	Day	15% 11% 26% 28% 13% 6%	479
	21st to end	Day	14% 13% 32% 21% 14% 7%	539
September	1st to 10th	Day	18% 13% 23% 25% 14% 7%	490
	11th to 20th	Day	13% 12% 23% 23% 17% 11%	490
	21st to end	Day	17% 14% 28% 24% 13% 4	490
October	1st to 10th	Day	23% 13% 28% 18% 15% 3	490
	11th to 20th	Day	28% 20% 25% 18% 8% 2	490
	21st to end	Day	34% 16% 30% 16% 4	493
November	1st to 10th	Day	28% 22% 24% 19% 7% 1	395
	11th to 20th	Day	31% 26% 24% 16% 2 1	277
	21st to end	Day	39% 19% 34% 9%	200
December	1st to 10th	Day	37% 23% 29% 9% 3 1	200
	11th to 20th	Day	34% 28% 28% 10% 2	200
	21st to end	Day	33% 24% 30% 14%	220
January	1st to 10th	Night	30% 26% 30% 12% 2	800
	11th to 20th	Night	29% 24% 30% 15% 3	800
	21st to end	Night	22% 25% 34% 17% 3	880
February	1st to 10th	Night	31% 22% 31% 16% 1	800
	11th to 20th	Night	27% 26% 31% 14% 2	783
	21st to end	Night	29% 24% 29% 15% 3	629
March	1st to 10th	Night	28% 21% 29% 19% 3	760
	11th to 20th	Night	27% 23% 27% 20% 3	760
	21st to end	Night	28% 20% 25% 19% 6%	836
April	1st to 10th	Night	28% 17% 30% 22% 3	760
	11th to 20th	Night	26% 19% 26% 21% 7% 1	751
	21st to end	Night	27% 14% 24% 27% 7%	749
May	1st to 10th	Night	25% 13% 22% 31% 9% 1	412
	11th to 20th	Night	16% 10% 33% 33% 7% 1	374
	21st to end	Night	13% 10% 29% 34% 14%	411
June	1st to 10th	Night	21% 8% 20% 39% 12% 1	380
	11th to 20th	Night	17% 8% 23% 36% 16%	380
	21st to end	Night	16% 6% 27% 42% 9% 1	380
July	1st to 10th	Night	10% 5% 19% 47% 18% 2	370
	11th to 20th	Night	12% 4 19% 44% 19% 2	368
	21st to end	Night	13% 6% 22% 44% 13% 1	416
August	1st to 10th	Night	14% 5% 22% 37% 21% 1	534
	11th to 20th	Night	14% 6% 22% 31% 25% 2	607
	21st to end	Night	16% 6% 21% 35% 21% 1	836
September	1st to 10th	Night	17% 7% 24% 31% 19% 2	760
	11th to 20th	Night	17% 7% 19% 30% 23% 4	760
	21st to end	Night	19% 12% 21% 29% 17% 2	760
October	1st to 10th	Night	28% 11% 23% 21% 16% 1	760
	11th to 20th	Night	28% 14% 28% 23% 7% 1	760
	21st to end	Night	35% 16% 26% 20% 3	836
November	1st to 10th	Night	27% 17% 28% 21% 7%	780
	11th to 20th	Night	29% 21% 26% 17% 6% 1	800
	21st to end	Night	30% 23% 28% 16% 4	800
December	1st to 10th	Night	34% 25% 26% 14% 2	800
	11th to 20th	Night	33% 23% 27% 14% 3	800
	21st to end	Night	33% 23% 27% 14% 2	880

Page generated at 2025-02-18 03:26:27. Version ac07

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