Sassafras Ridge
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Sassafras Ridge clear sky chart from 2005-11-06 to 2024-03-23.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
43%
24102
13%
80167
9%
23994
47%
23994
11%
60699

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 10thNight
22%
756
13%
4029
5%
737
30%
737
5%
2794
January11th to 20thNight
22%
759
18%
3975
5%
740
28%
740
5%
2805
January21st to endNight
22%
833
9%
4459
6%
814
30%
814
5%
3351
February1st to 10thNight
29%
760
15%
2280
8%
760
36%
760
12%
1751
February11th to 20thNight
17%
743
10%
2219
4%
740
24%
740
9%
1757
February21st to endNight
16%
628
11%
1884
4%
628
22%
628
7%
1527
March1st to 10thNight
24%
760
14%
2220
8%
760
30%
760
11%
1702
March11th to 20thNight
25%
760
12%
2090
6%
760
30%
760
11%
1665
March21st to endNight
26%
801
9%
2201
5%
801
29%
801
12%
1743
April1st to 10thNight
33%
681
14%
1941
8%
681
39%
681
15%
1437
April11th to 20thNight
38%
533
19%
1771
13%
533
47%
533
15%
1233
April21st to endNight
43%
540
15%
1620
9%
540
47%
540
14%
1217
May1st to 10thNight
42%
540
10%
1620
5%
540
46%
540
12%
1255
May11th to 20thNight
50%
531
9%
1593
6%
531
52%
531
12%
1285
May21st to endNight
58%
582
10%
1744
7%
582
59%
582
14%
1345
June1st to 10thNight
61%
540
9%
1620
7%
540
62%
540
14%
1273
June11th to 20thNight
70%
540
11%
1620
9%
540
71%
540
18%
1198
June21st to endNight
66%
540
11%
1620
10%
540
67%
540
15%
1231
July1st to 10thNight
64%
525
8%
1575
7%
525
65%
525
12%
1272
July11th to 20thNight
69%
522
7%
1566
6%
522
69%
522
13%
1252
July21st to endNight
68%
591
8%
1672
7%
558
68%
558
13%
1314
August1st to 10thNight
69%
537
10%
1600
11%
534
69%
534
15%
1243
August11th to 20thNight
64%
534
11%
1661
12%
534
65%
534
12%
1315
August21st to endNight
64%
594
10%
1980
10%
594
65%
594
12%
1560
September1st to 10thNight
61%
692
10%
1952
9%
692
61%
692
13%
1554
September11th to 20thNight
60%
720
12%
1980
10%
720
60%
720
14%
1567
September21st to endNight
57%
720
16%
1980
11%
720
62%
720
17%
1486
October1st to 10thNight
57%
720
19%
1980
15%
720
61%
720
20%
1429
October11th to 20thNight
43%
720
17%
2108
12%
720
50%
720
15%
1571
October21st to endNight
44%
792
18%
2378
13%
792
51%
792
16%
1730
November1st to 10thNight
49%
740
19%
2406
17%
740
55%
740
18%
1665
November11th to 20thNight
39%
760
17%
2470
12%
760
47%
760
12%
1832
November21st to endNight
38%
760
14%
2470
9%
760
44%
760
12%
1888
December1st to 10thNight
28%
760
12%
2470
7%
760
34%
760
9%
1968
December11th to 20thNight
32%
759
14%
2964
10%
759
37%
759
8%
2255
December21st to endNight
27%
829
8%
4449
6%
817
33%
817
5%
3229

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 ForecastData
Points
Cloud CoverDay
14%9%47%6%45%5%6%7%34%
79079
Night
13%10%47%6%35%5%5%7%37%
80822
TransparencyDay
31%36%7%12%11%2
78802
Night
30%35%8%13%11%3
80618
SeeingDay
22%13%23%20%15%8%
13962
Night
19%11%19%27%20%4
24120

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
17%11%46%5%35%6%5%6%30%
2836
11th to 20thDay
14%10%5%13%5%34445%33%
2840
21st to endDay
17%15%7%6%5%23345%33%
3133
February1st to 10thDay
18%11%5%8%5%35%5%45%33%
1900
11th to 20thDay
19%10%5%8%7%23445%32%
1848
21st to endDay
20%11%38%6%33445%33%
1570
March1st to 10thDay
16%9%46%5%3445%6%36%
1958
11th to 20thDay
17%10%37%7%35%446%33%
2090
21st to endDay
15%13%46%6%45%45%6%33%
2200
April1st to 10thDay
11%9%36%5%36%5%6%8%39%
2034
11th to 20thDay
16%7%26%5%35%447%41%
2138
21st to endDay
14%8%46%6%35%45%7%38%
2340
May1st to 10thDay
13%8%36%6%36%5%6%6%37%
2340
11th to 20thDay
16%8%47%8%5%6%5%5%6%30%
2301
21st to endDay
11%7%38%7%5%6%6%7%9%29%
2531
June1st to 10thDay
11%7%47%7%5%7%7%8%8%30%
2340
11th to 20thDay
7%6%39%8%5%7%7%7%10%32%
2340
21st to endDay
10%7%36%8%46%6%7%11%31%
2340
July1st to 10thDay
11%8%5%8%9%5%8%8%7%8%24%
2340
11th to 20thDay
13%7%39%8%5%8%7%8%8%24%
2340
21st to endDay
11%7%38%10%6%8%7%7%10%23%
2547
August1st to 10thDay
11%7%39%8%6%7%6%9%10%25%
2327
11th to 20thDay
13%7%48%9%48%6%7%8%26%
2235
21st to endDay
14%7%47%8%6%8%7%7%7%25%
2376
September1st to 10thDay
13%7%48%7%46%6%7%7%32%
1990
11th to 20thDay
15%8%37%6%45%6%6%8%32%
1980
21st to endDay
14%6%36%6%35%5%5%7%40%
1980
October1st to 10thDay
11%6%36%5%35%5%5%5%46%
1980
11th to 20thDay
12%7%25%43445%6%48%
1850
21st to endDay
14%6%34434446%48%
1976
November1st to 10thDay
11%7%15%423436%53%
1672
11th to 20thDay
12%7%36%5%2445%5%46%
1710
21st to endDay
13%10%36%5%2445%6%42%
1710
December1st to 10thDay
19%11%5%7%5%45%5%35%31%
1710
11th to 20thDay
15%9%48%6%35%45%5%36%
2153
21st to endDay
14%11%6%9%6%25%45%6%32%
3124
January1st to 10thNight
15%15%5%7%5%34436%32%
4109
11th to 20thNight
18%11%5%7%5%35%446%31%
4120
21st to endNight
19%17%5%7%43333333%
4521
February1st to 10thNight
14%10%5%8%6%44435%36%
2280
11th to 20thNight
18%11%6%9%6%3433433%
2218
21st to endNight
19%13%49%5%3444431%
1884
March1st to 10thNight
14%11%5%8%5%34446%37%
2220
11th to 20thNight
16%9%47%7%3445%6%34%
2090
21st to endNight
14%12%5%7%6%246%45%35%
2201
April1st to 10thNight
13%8%35%5%34447%43%
1941
11th to 20thNight
12%9%45%42445%6%44%
1771
21st to endNight
14%8%25%5%335%5%8%43%
1620
May1st to 10thNight
12%7%37%6%36%6%5%8%37%
1620
11th to 20thNight
12%7%46%6%45%5%6%9%37%
1592
21st to endNight
8%8%46%7%46%6%6%10%36%
1744
June1st to 10thNight
9%6%36%7%46%7%8%10%35%
1620
11th to 20thNight
6%4245%36%6%9%12%42%
1620
21st to endNight
8%6%36%6%46%6%6%10%39%
1620
July1st to 10thNight
10%6%36%7%47%7%9%9%32%
1620
11th to 20thNight
9%5%36%6%36%6%10%12%34%
1620
21st to endNight
8%5%37%6%47%7%9%12%32%
1771
August1st to 10thNight
9%6%26%6%36%7%7%11%37%
1611
11th to 20thNight
9%6%36%7%5%7%7%7%9%35%
1661
21st to endNight
11%7%36%7%46%6%8%9%34%
1980
September1st to 10thNight
11%6%46%7%45%5%7%7%39%
1952
11th to 20thNight
11%8%37%6%445%6%7%39%
1980
21st to endNight
11%6%36%5%35%5%46%47%
1980
October1st to 10thNight
11%6%25%5%23445%53%
1980
11th to 20thNight
14%7%35%5%23445%47%
2108
21st to endNight
12%7%45%423445%50%
2378
November1st to 10thNight
11%8%25%434345%50%
2406
11th to 20thNight
13%9%36%424346%46%
2470
21st to endNight
13%10%35%5%345%46%41%
2470
December1st to 10thNight
17%11%5%9%6%35%445%29%
2470
11th to 20thNight
13%12%5%8%5%34445%36%
3042
21st to endNight
14%13%7%10%7%45%5%5%6%24%
4532

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
38%26%6%12%16%2
2837
11th to 20thDay
40%26%6%9%17%2
2840
21st to endDay
44%21%5%14%13%1
3133
February1st to 10thDay
34%33%6%11%12%3
1900
11th to 20thDay
35%34%5%11%11%4
1858
21st to endDay
36%33%6%9%12%4
1570
March1st to 10thDay
30%34%6%11%14%4
1958
11th to 20thDay
34%35%9%10%9%3
2090
21st to endDay
35%37%9%13%7%1
2200
April1st to 10thDay
25%38%8%15%11%2
2034
11th to 20thDay
26%35%5%12%19%3
2138
21st to endDay
29%37%7%17%8%2
2340
May1st to 10thDay
31%38%8%11%10%2
2340
11th to 20thDay
33%39%8%10%8%1
2305
21st to endDay
27%39%10%15%8%1
2531
June1st to 10thDay
29%40%11%14%5%1
2340
11th to 20thDay
25%40%12%14%7%1
2340
21st to endDay
26%40%11%11%9%3
2340
July1st to 10thDay
33%42%10%9%5%1
2275
11th to 20thDay
32%43%10%6%8%2
2271
21st to endDay
30%44%11%11%4
2405
August1st to 10thDay
29%41%12%14%41
2314
11th to 20thDay
31%40%11%10%7%
2235
21st to endDay
35%41%8%9%6%2
2376
September1st to 10thDay
31%39%8%11%10%2
1990
11th to 20thDay
33%38%6%11%12%1
1980
21st to endDay
27%37%6%11%14%5%
1980
October1st to 10thDay
20%36%6%14%19%4
1980
11th to 20thDay
25%36%5%15%15%5%
1850
21st to endDay
23%37%5%15%17%5%
1976
November1st to 10thDay
15%40%411%22%7%
1672
11th to 20thDay
24%39%414%15%5%
1710
21st to endDay
25%39%413%14%4
1710
December1st to 10thDay
33%39%5%11%11%1
1710
11th to 20thDay
34%32%8%11%14%2
2150
21st to endDay
39%26%6%18%10%1
3124
January1st to 10thNight
38%24%8%13%14%2
4109
11th to 20thNight
39%25%5%13%11%8%
4120
21st to endNight
47%22%5%8%15%2
4521
February1st to 10thNight
32%34%7%10%15%2
2280
11th to 20thNight
34%35%6%11%11%4
2219
21st to endNight
38%34%5%9%12%2
1884
March1st to 10thNight
30%35%7%11%14%4
2220
11th to 20thNight
31%37%8%12%10%2
2090
21st to endNight
31%36%10%14%7%1
2201
April1st to 10thNight
24%36%10%15%14%2
1941
11th to 20thNight
22%35%7%15%17%4
1771
21st to endNight
25%38%9%18%9%1
1620
May1st to 10thNight
27%39%12%12%9%1
1620
11th to 20thNight
29%41%12%12%5%
1593
21st to endNight
24%41%12%16%6%2
1745
June1st to 10thNight
28%40%11%14%7%
1620
11th to 20thNight
20%40%14%18%5%2
1620
21st to endNight
23%41%12%13%8%4
1620
July1st to 10thNight
30%41%11%11%7%1
1575
11th to 20thNight
26%43%14%8%5%3
1566
21st to endNight
23%45%14%13%4
1672
August1st to 10thNight
23%43%12%17%4
1600
11th to 20thNight
29%40%11%12%8%1
1661
21st to endNight
29%39%13%12%5%1
1980
September1st to 10thNight
30%39%10%11%8%3
1952
11th to 20thNight
28%40%9%11%12%
1980
21st to endNight
23%38%6%13%14%5%
1980
October1st to 10thNight
20%37%6%12%21%5%
1980
11th to 20thNight
25%37%6%14%14%4
2108
21st to endNight
23%37%415%17%5%
2378
November1st to 10thNight
16%40%5%14%18%8%
2406
11th to 20thNight
24%39%414%15%5%
2470
21st to endNight
28%38%413%13%4
2470
December1st to 10thNight
31%40%6%11%9%3
2470
11th to 20thNight
34%33%6%11%15%1
3044
21st to endNight
40%26%8%16%9%1
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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
34%24%31%9%2
270
11th to 20thDay
36%28%20%12%4
270
21st to endDay
30%32%28%7%3
297
February1st to 10thDay
34%23%32%10%1
270
11th to 20thDay
48%19%28%41
270
21st to endDay
45%26%22%6%
225
March1st to 10thDay
32%19%31%13%5%
328
11th to 20thDay
27%27%25%16%5%1
460
21st to endDay
29%21%28%17%41
470
April1st to 10thDay
26%15%27%21%10%1
420
11th to 20thDay
22%21%25%19%11%3
412
21st to endDay
25%15%24%20%12%3
420
May1st to 10thDay
22%17%29%16%10%5%
423
11th to 20thDay
19%8%28%22%15%8%
447
21st to endDay
16%9%19%28%16%12%
485
June1st to 10thDay
18%7%19%26%20%11%
450
11th to 20thDay
11%5%19%26%23%17%
450
21st to endDay
14%6%25%26%16%14%
450
July1st to 10thDay
14%415%23%26%18%
445
11th to 20thDay
13%415%24%25%20%
444
21st to endDay
13%213%24%26%22%
488
August1st to 10thDay
18%5%16%19%22%20%
446
11th to 20thDay
17%313%28%26%13%
439
21st to endDay
18%311%22%26%20%
495
September1st to 10thDay
11%413%26%31%14%
450
11th to 20thDay
17%5%13%24%27%13%
450
21st to endDay
17%8%16%28%24%8%
450
October1st to 10thDay
18%7%21%25%20%9%
450
11th to 20thDay
20%12%25%22%19%3
450
21st to endDay
23%11%26%24%13%3
491
November1st to 10thDay
20%15%31%24%9%1
270
11th to 20thDay
25%18%31%21%5%
270
21st to endDay
20%25%34%13%7%1
270
December1st to 10thDay
34%19%29%14%4
270
11th to 20thDay
27%18%33%19%41
270
21st to endDay
34%19%33%10%3
297
January1st to 10thNight
28%18%25%24%5%
760
11th to 20thNight
30%20%24%21%5%
760
21st to endNight
22%20%30%25%2
836
February1st to 10thNight
22%17%29%28%5%
760
11th to 20thNight
31%19%29%20%2
743
21st to endNight
32%20%28%16%4
628
March1st to 10thNight
21%21%30%24%5%
760
11th to 20thNight
23%18%27%22%8%1
760
21st to endNight
23%16%29%24%8%
801
April1st to 10thNight
20%17%26%26%10%1
681
11th to 20thNight
21%13%22%28%14%2
533
21st to endNight
17%10%23%33%16%1
540
May1st to 10thNight
16%11%23%29%19%2
540
11th to 20thNight
15%7%19%32%24%4
531
21st to endNight
14%412%31%32%7%
584
June1st to 10thNight
14%111%32%35%6%
540
11th to 20thNight
9%210%30%36%13%
540
21st to endNight
12%29%30%38%9%
540
July1st to 10thNight
14%25%23%46%11%
525
11th to 20thNight
11%2424%43%16%
522
21st to endNight
9%25%23%46%15%
591
August1st to 10thNight
12%4423%46%12%
537
11th to 20thNight
14%36%28%40%10%
534
21st to endNight
15%27%20%44%12%
594
September1st to 10thNight
13%39%25%39%11%
692
11th to 20thNight
16%48%28%38%7%
720
21st to endNight
15%413%28%36%4
720
October1st to 10thNight
16%7%14%26%28%8%
720
11th to 20thNight
18%9%21%28%21%3
720
21st to endNight
17%12%21%32%16%3
792
November1st to 10thNight
18%9%18%31%21%4
740
11th to 20thNight
19%14%21%31%12%2
760
21st to endNight
22%13%22%28%14%1
760
December1st to 10thNight
27%16%22%27%8%
760
11th to 20thNight
25%13%24%30%8%1
760
21st to endNight
28%13%24%29%6%
836
Page generated at 2024-03-19 23:31:06. Version ac07

Copyright © 2024 Attilla Danko.


Sassafras Ridge Clear Sky Chart |Charts Home