In a small bowl, combine the tomatoes, red onion, cilantro, olive oil, lemon zest, garlic, cumin, cinnamon, turmeric, paprika, cayenne and salt. Toss gently to mix.
Transfer to a serving bowl, cover, and let stand at room temperature for about 1 hour to allow the flavors to develop, or refrigerate for up to 8 hours. Serve at cool room temperature.