Apple River
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Apple River clear sky chart from 2005-11-06 to 2024-11-04.

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
33%
25573
16%
96722
10%
25286
41%
25286
18%
63880

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
21%
939
9%
4395
5%
926
29%
926
11%
3205
January11th to 20thNight
18%
950
11%
4369
3%
930
24%
930
8%
3350
January21st to endNight
18%
1040
6%
4607
2%
1023
24%
1023
8%
3671
February1st to 10thNight
21%
950
12%
2470
4%
950
27%
950
18%
1826
February11th to 20thNight
22%
828
18%
2307
6%
828
31%
828
20%
1594
February21st to endNight
17%
628
17%
1884
4%
628
29%
628
17%
1319
March1st to 10thNight
19%
757
18%
3685
5%
745
27%
745
12%
2267
March11th to 20thNight
29%
609
23%
3486
12%
592
40%
592
15%
1750
March21st to endNight
21%
624
8%
3521
8%
605
30%
605
8%
2632
April1st to 10thNight
23%
570
16%
1900
8%
570
34%
570
18%
1265
April11th to 20thNight
27%
563
19%
1875
12%
563
39%
563
18%
1246
April21st to endNight
31%
570
14%
1891
8%
570
40%
570
20%
1271
May1st to 10thNight
29%
567
18%
2612
7%
559
38%
559
14%
1709
May11th to 20thNight
32%
552
15%
2445
9%
541
40%
541
16%
1502
May21st to endNight
42%
608
14%
2707
8%
593
49%
593
22%
1423
June1st to 10thNight
49%
570
17%
1520
8%
570
55%
570
34%
962
June11th to 20thNight
45%
570
19%
1520
10%
570
50%
570
36%
951
June21st to endNight
48%
570
18%
1520
9%
570
53%
570
31%
996
July1st to 10thNight
66%
546
14%
2440
12%
535
70%
535
23%
1538
July11th to 20thNight
60%
540
19%
2195
14%
533
64%
533
33%
1098
July21st to endNight
63%
606
16%
2477
16%
569
66%
569
26%
1397
August1st to 10thNight
66%
554
24%
2448
20%
545
71%
545
26%
1308
August11th to 20thNight
64%
553
18%
2654
23%
543
69%
543
24%
1447
August21st to endNight
62%
611
18%
3149
25%
605
67%
605
23%
1719
September1st to 10thNight
59%
570
26%
1900
24%
570
66%
570
35%
1039
September11th to 20thNight
56%
582
29%
1912
26%
582
62%
582
33%
1072
September21st to endNight
47%
760
24%
2092
14%
760
54%
760
34%
1262
October1st to 10thNight
45%
760
20%
2394
15%
740
51%
740
28%
1506
October11th to 20thNight
32%
760
17%
2623
10%
740
42%
740
20%
1762
October21st to endNight
27%
836
12%
3413
10%
814
35%
814
13%
2508
November1st to 10thNight
29%
755
24%
2452
15%
755
41%
755
26%
1467
November11th to 20thNight
22%
788
16%
2498
8%
788
31%
788
16%
1728
November21st to endNight
22%
950
17%
2660
7%
950
31%
950
21%
1837
December1st to 10thNight
20%
950
11%
2660
4%
950
27%
950
16%
1981
December11th to 20thNight
22%
949
12%
3199
3%
948
29%
948
13%
2317
December21st to endNight
14%
1038
7%
4842
2%
1026
23%
1026
6%
3955

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
13%9%38%5%45%45%7%37%
101484
Night
13%9%48%5%4435%6%39%
97625
TransparencyDay
44%6%12%23%13%1
105025
Night
44%6%11%23%14%2
102224
SeeingDay
17%14%31%24%12%3
15878
Night
17%11%32%28%10%1
25710

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
11%13%8%15%7%5%334427%
2527
11th to 20thDay
10%11%5%15%7%5%6%7%9%6%20%
2530
21st to endDay
15%20%8%12%5%34246%21%
3016
February1st to 10thDay
12%13%5%10%6%45%45%6%30%
1710
11th to 20thDay
13%10%48%5%5%6%35%6%36%
1759
21st to endDay
13%12%410%6%44336%34%
1570
March1st to 10thDay
14%9%36%44435%6%43%
3120
11th to 20thDay
11%6%38%5%4445%8%42%
3442
21st to endDay
21%14%410%6%4435%6%23%
4062
April1st to 10thDay
18%13%37%5%4435%6%31%
2280
11th to 20thDay
17%10%37%5%4435%6%34%
2254
21st to endDay
20%9%37%45%435%7%34%
2289
May1st to 10thDay
16%8%37%6%45%36%7%35%
4269
11th to 20thDay
13%7%27%445%45%6%42%
4399
21st to endDay
12%7%37%5%5%5%46%8%39%
4824
June1st to 10thDay
10%5%27%45%5%5%6%8%43%
2660
11th to 20thDay
11%6%25%445%47%9%42%
2660
21st to endDay
11%7%26%5%5%6%5%6%8%38%
2660
July1st to 10thDay
10%8%38%5%5%6%5%7%9%34%
4440
11th to 20thDay
5%415%5%4446%10%51%
4440
21st to endDay
7%6%38%5%6%6%47%9%39%
4813
August1st to 10thDay
9%6%27%5%46%5%7%9%40%
4235
11th to 20thDay
11%5%26%445%46%8%46%
3855
21st to endDay
8%6%26%44446%8%47%
4180
September1st to 10thDay
12%5%27%445%348%46%
2280
11th to 20thDay
12%5%15%32435%8%53%
2247
21st to endDay
12%8%25%44435%8%44%
2085
October1st to 10thDay
12%7%35%433346%48%
1900
11th to 20thDay
17%9%38%44435%5%39%
1900
21st to endDay
18%9%27%44335%6%40%
1961
November1st to 10thDay
12%8%37%5%44446%44%
1699
11th to 20thDay
13%13%38%5%5%436%6%34%
1677
21st to endDay
13%12%48%5%43346%38%
1520
December1st to 10thDay
14%13%49%6%44446%32%
1520
11th to 20thDay
13%13%410%6%45%45%6%28%
1918
21st to endDay
20%21%9%12%5%4334415%
2783
January1st to 10thNight
12%12%7%13%6%44345%29%
4428
11th to 20thNight
12%16%6%14%7%445%8%5%20%
4440
21st to endNight
16%18%8%11%6%5%4345%22%
4646
February1st to 10thNight
12%13%410%6%5%5%445%32%
2470
11th to 20thNight
10%10%49%6%4435%5%40%
2306
21st to endNight
15%12%48%443345%37%
1884
March1st to 10thNight
18%10%35%43434441%
3733
11th to 20thNight
9%7%25%44435%8%47%
3548
21st to endNight
24%12%5%11%443345%25%
3568
April1st to 10thNight
16%11%36%444346%40%
1900
11th to 20thNight
17%8%37%444246%40%
1875
21st to endNight
16%9%37%5%5%5%36%7%36%
1891
May1st to 10thNight
17%9%28%5%45%45%7%35%
2629
11th to 20thNight
13%7%26%5%45%46%6%41%
2506
21st to endNight
9%6%26%34446%9%46%
2743
June1st to 10thNight
8%428%345%47%7%47%
1520
11th to 20thNight
11%5%244445%6%9%46%
1520
21st to endNight
11%6%26%446%36%7%45%
1520
July1st to 10thNight
13%9%26%34446%8%40%
2530
11th to 20thNight
4325%43446%10%56%
2530
21st to endNight
6%425%445%48%8%49%
2750
August1st to 10thNight
7%426%44446%8%51%
2701
11th to 20thNight
8%6%25%44435%7%52%
2978
21st to endNight
9%5%25%44435%8%50%
3476
September1st to 10thNight
9%425%344347%56%
1900
11th to 20thNight
10%416%34445%6%52%
1912
21st to endNight
10%6%15%335%45%7%51%
2092
October1st to 10thNight
11%5%25%34435%6%52%
2280
11th to 20thNight
15%8%35%44325%6%45%
2280
21st to endNight
17%8%36%5%5%435%6%38%
2636
November1st to 10thNight
11%8%37%43335%6%49%
2452
11th to 20thNight
12%12%49%5%5%5%35%5%36%
2498
21st to endNight
16%10%38%5%33347%38%
2660
December1st to 10thNight
13%12%410%6%5%5%45%6%30%
2660
11th to 20thNight
13%13%5%10%5%4445%7%30%
3279
21st to endNight
20%17%6%12%5%5%4345%19%
4884

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
61%5%12%15%6%
2528
11th to 20thDay
58%8%15%11%7%1
2530
21st to endDay
66%5%11%13%5%
3016
February1st to 10thDay
54%5%13%18%10%1
1710
11th to 20thDay
48%5%12%23%10%2
1768
21st to endDay
51%7%10%20%9%2
1570
March1st to 10thDay
42%7%11%26%12%3
3120
11th to 20thDay
39%7%12%31%11%1
3442
21st to endDay
61%8%12%13%5%1
4062
April1st to 10thDay
53%6%10%21%10%
2280
11th to 20thDay
50%7%9%21%11%2
2254
21st to endDay
50%6%11%19%12%2
2289
May1st to 10thDay
45%8%11%19%15%
4307
11th to 20thDay
42%8%9%30%12%
4403
21st to endDay
40%9%11%22%14%4
4837
June1st to 10thDay
37%9%12%24%16%1
2660
11th to 20thDay
37%7%13%23%19%2
2660
21st to endDay
42%8%14%23%11%2
2660
July1st to 10thDay
46%6%13%25%9%1
4371
11th to 20thDay
28%6%16%31%16%1
4365
21st to endDay
40%7%15%18%18%2
4662
August1st to 10thDay
38%7%15%26%13%1
4220
11th to 20thDay
36%5%13%30%15%1
3894
21st to endDay
34%5%14%31%15%2
4179
September1st to 10thDay
37%8%10%25%18%2
2280
11th to 20thDay
31%6%12%32%17%2
2247
21st to endDay
38%6%10%27%18%1
2085
October1st to 10thDay
24%46%37%28%1
3160
11th to 20thDay
34%310%25%25%3
3140
21st to endDay
42%49%29%14%3
3212
November1st to 10thDay
40%6%14%25%13%2
1699
11th to 20thDay
50%6%14%19%9%1
1677
21st to endDay
49%6%17%21%7%1
1520
December1st to 10thDay
53%7%13%17%8%2
1520
11th to 20thDay
54%7%16%14%8%1
1915
21st to endDay
72%7%9%8%4
2783
January1st to 10thNight
56%7%11%17%8%
4428
11th to 20thNight
62%6%11%13%8%
4440
21st to endNight
67%49%14%5%1
4646
February1st to 10thNight
52%5%13%17%12%1
2470
11th to 20thNight
46%7%11%22%14%1
2307
21st to endNight
50%5%12%20%10%3
1884
March1st to 10thNight
46%6%11%21%13%3
3733
11th to 20thNight
33%7%11%32%15%2
3548
21st to endNight
62%6%8%17%6%1
3568
April1st to 10thNight
46%6%11%22%13%2
1900
11th to 20thNight
47%6%8%19%18%3
1875
21st to endNight
46%6%13%20%12%2
1891
May1st to 10thNight
46%8%12%15%17%2
2656
11th to 20thNight
40%9%11%23%15%1
2507
21st to endNight
31%9%14%25%19%2
2751
June1st to 10thNight
32%9%13%25%19%2
1520
11th to 20thNight
32%7%11%25%21%3
1520
21st to endNight
37%8%14%22%16%4
1520
July1st to 10thNight
42%5%16%23%12%3
2490
11th to 20thNight
25%416%35%18%2
2482
21st to endNight
31%8%18%20%19%4
2662
August1st to 10thNight
30%5%15%31%17%1
2692
11th to 20thNight
33%313%33%17%1
3005
21st to endNight
32%5%12%29%17%4
3476
September1st to 10thNight
29%6%12%27%25%2
1900
11th to 20thNight
31%6%12%31%18%3
1912
21st to endNight
32%7%10%30%19%2
2092
October1st to 10thNight
25%36%35%29%2
3800
11th to 20thNight
33%39%23%29%3
3779
21st to endNight
45%49%26%15%2
4335
November1st to 10thNight
37%5%12%26%18%3
2452
11th to 20thNight
49%6%13%19%12%1
2498
21st to endNight
47%5%13%24%10%1
2660
December1st to 10thNight
54%6%12%20%8%1
2660
11th to 20thNight
53%6%15%18%7%1
3281
21st to endNight
68%6%8%12%4
4884

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
20%16%32%25%7%1
270
11th to 20thDay
21%17%43%15%31
270
21st to endDay
22%21%36%17%31
297
February1st to 10thDay
18%25%37%17%3
270
11th to 20thDay
23%27%30%17%4
270
21st to endDay
23%24%41%11%1
225
March1st to 10thDay
18%24%44%11%3
270
11th to 20thDay
24%22%36%12%41
270
21st to endDay
30%18%30%17%41
442
April1st to 10thDay
28%19%32%15%5%
460
11th to 20thDay
28%18%26%19%7%1
452
21st to endDay
24%17%30%19%8%2
460
May1st to 10thDay
20%16%32%24%6%2
572
11th to 20thDay
21%15%31%21%10%2
675
21st to endDay
17%13%29%24%13%5%
734
June1st to 10thDay
9%11%31%29%14%5%
680
11th to 20thDay
13%10%35%28%11%4
680
21st to endDay
16%12%29%28%11%4
680
July1st to 10thDay
10%424%31%21%10%
671
11th to 20thDay
9%6%30%31%18%6%
668
21st to endDay
9%5%28%34%18%6%
739
August1st to 10thDay
7%424%36%23%6%
676
11th to 20thDay
13%7%24%25%23%9%
557
21st to endDay
10%6%22%33%21%7%
539
September1st to 10thDay
14%9%26%28%18%5%
490
11th to 20thDay
11%424%32%22%7%
490
21st to endDay
16%16%26%24%16%3
485
October1st to 10thDay
16%16%29%26%12%1
300
11th to 20thDay
22%25%30%17%7%
300
21st to endDay
30%17%31%17%41
330
November1st to 10thDay
19%18%38%18%7%2
279
11th to 20thDay
19%23%36%16%6%
270
21st to endDay
25%14%42%16%4
270
December1st to 10thDay
17%23%39%15%6%1
270
11th to 20thDay
16%18%37%22%6%
270
21st to endDay
24%24%37%14%1
297
January1st to 10thNight
16%17%38%23%6%1
950
11th to 20thNight
18%17%38%22%41
950
21st to endNight
21%12%37%24%4
1045
February1st to 10thNight
20%15%37%23%5%
950
11th to 20thNight
16%17%38%25%3
832
21st to endNight
24%17%38%18%3
628
March1st to 10thNight
24%15%36%20%5%
760
11th to 20thNight
19%12%35%27%6%
612
21st to endNight
24%13%36%22%4
627
April1st to 10thNight
20%18%35%23%4
570
11th to 20thNight
21%16%31%26%6%
563
21st to endNight
21%12%31%28%7%1
570
May1st to 10thNight
17%11%38%26%6%1
570
11th to 20thNight
20%7%34%30%10%
561
21st to endNight
13%434%34%14%1
617
June1st to 10thNight
9%431%44%11%
570
11th to 20thNight
13%434%37%12%
570
21st to endNight
12%5%28%40%15%1
570
July1st to 10thNight
8%318%39%29%4
555
11th to 20thNight
7%325%38%24%3
552
21st to endNight
7%221%44%25%1
624
August1st to 10thNight
6%317%45%27%2
567
11th to 20thNight
10%116%39%29%5%
564
21st to endNight
10%319%43%22%3
627
September1st to 10thNight
10%5%22%38%20%5%
570
11th to 20thNight
11%424%33%24%4
582
21st to endNight
13%10%27%33%17%1
760
October1st to 10thNight
14%8%28%33%16%1
760
11th to 20thNight
19%13%32%27%9%
760
21st to endNight
22%15%32%24%6%
836
November1st to 10thNight
16%13%37%23%9%1
755
11th to 20thNight
18%18%36%22%5%
788
21st to endNight
20%15%37%20%7%
950
December1st to 10thNight
20%15%38%22%5%
950
11th to 20thNight
21%14%35%24%5%
950
21st to endNight
27%16%35%20%2
1045
Page generated at 2024-11-01 21:47:29. Version ac07

Copyright © 2024 Attilla Danko.


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