Frankfurt to Porto flights, non-stop

The way back

1. M
2. T
3. W
4. T
5. F
6. S
7. S
8. Nov16–no fare seen
9. 17–no fare seen
10. 18€20806:00
11. 19–no fare seen
12. 20€12912:20
13. 21€15712:30
14. 22€9007:20
15. 23–no fare seen
16. 24€21612:35
17. 25€20312:35
18. 26€24206:00
19. 27€12412:20
20. 28€18816:10
21. 29€17807:20
22. 30–no fare seen
23. Dec1€17912:35
24. 2–no fare seen
25. 3–no fare seen
26. 4–no fare seen
27. 5€13116:10
28. 6–no fare seen
29. 7–no fare seen
30. 8–no fare seen
31. 9–no fare seen
32. 10–no fare seen
33. 11–no fare seen
34. 12–no fare seen
35. 13–no fare seen
36. 14€15312:30
37. 15€15312:35
38. 16–no fare seen
39. 17€15712:35
40. 18€2712:20
41. 19–no fare seen
42. 20–no fare seen
43. 21–no fare seen
44. 22–no fare seen
45. 23–no fare seen
46. 24–no fare seen
47. 25–no fare seen
48. 26€13606:00
49. 27€8807:20
50. 28–no fare seen
51. 29–no fare seen
52. 30–no fare seen
53. 31–no fare seen
54. Jan1–no fare seen
55. 2–no fare seen
56. 3€29107:20
57. 4–no fare seen
58. 5–no fare seen
59. 6–no fare seen
60. 7–no fare seen
61. 8–no fare seen
62. 9–no fare seen
63. 10–no fare seen
64. 11€32206:00
65. 12–no fare seen
66. 13–no fare seen
67. 14–no fare seen
68. 15–no fare seen
69. 16–no fare seen
70. 17–no fare seen
71. 18–no fare seen
72. 19–no fare seen
73. 20–no fare seen
74. 21–no fare seen
75. 22–no fare seen
76. 23–no fare seen
77. 24–no fare seen
78. 25–no fare seen
79. 26–no fare seen
80. 27–no fare seen
81. 28–no fare seen
82. 29–no fare seen
83. 30–no fare seen
84. 31–no fare seen
85. Feb1€13716:10
86. 2–no fare seen
87. 3–no fare seen
88. 4–no fare seen
89. 5–no fare seen
90. 6–no fare seen
91. 7–no fare seen
92. 8–no fare seen
93. 9–no fare seen
94. 10–no fare seen
95. 11–no fare seen
96. 12–no fare seen
97. 13–no fare seen

Of the 21 days with a time, the day's cheapest flight leaves in the morning on 8, in the afternoon on 13 and in the evening on 0.

Porto to Frankfurt non-stop: from €27 on 18 Dec, with fares on 21 of the next 90 days.